Explanation:
The number of protons and neutrons. you can simply subtract the number of protons, or atomic number, from the mass number to get your final answer.
Use the following balanced equation to answer the questions below.
Which statement about the relationship between laws, hypothesis, and theories is true?
The question is incomplete, the complete question is;
Which statement about the relationship between laws, hypotheses, and theories is true?
A.
Laws that remain true over an extended period of time are considered theories.
B.
A theory that holds true for a long time is considered a law.
C.
If a law is not contradicted after a lot of testing, it may be considered a hypothesis.
D.
If a hypothesis is not contradicted after a lot of testing, it may be considered a law.
Answer:
If a hypothesis is not contradicted after a lot of testing, it may be considered a law.
Explanation:
A hypothesis is an intelligent guess which is put forward to explain a particular scientific observation. Hypothesis are temporary explanations that must be subjected to rigorous scientific investigation.
If a hypothesis holds true for some time it is regarded as a theory. The theory is also subjected to further rigorous scientific experiments to see if it can be regarded as a law.
If the statement of the hypothesis is not contradicted after a lot of testing, it may be considered a law.
45. The reaction Cl2(g) 2Cl(g) is A. Exothermic because breaking bonds requires energy B. Exothermic because breaking bonds releases energy C. Endothermic because breaking bonds requires energy D. Endothermic because breaking bonds releases energy
Answer:
C. Endothermic because breaking bonds require energy
Explanation:
The reaction as follows is given in this question:
Cl2(g) → 2Cl(g)
According to this equation, chlorine molecule (Cl2) is broken down into chlorine atoms (2Cl) by breaking the bonds that holds the two atoms in the molecule together. Breaking of chemical bonds require energy input to occur.
An endothermic reaction is a reaction in which energy is absorbed or used up rather than released. Based on this definition, the reaction involving the breaking of bonds in chlorine molecule is an ENDOTHERMIC REACTION because breaking bonds require energy.
Would an electron in the 1s orbital of lithium require the same energy to move to a higher energy level as an electron in the
1s orbital of silver?
Answer:
See explanation
Explanation:
We must remember that the energy required to move an electron from the 1s orbital to a higher energy level depends on the size of the nuclear charge.
The higher the nuclear charge, the more closely held the 1s electron of the atom is to the nucleus and the more difficult it is to excite this electron.
Hence, it requires more energy to excite the 1s electron of silver having a larger size of nuclear charge than it is to excite a 1s electron in lithium.
by acid-base reaction explain why thymol is sparingly soluble in water but soluble in 1M NaOH solution
Answer:
Sulphanilic acid is insoluble in both water as well as in acid because it can not form hydrogen bonding with the water molecule. But it is soluble in aqueous mineral acid like HF,HCl,HNO3 because they are able to form a hydrogen bond with mineral acids. Was this answer helpful?
g A solution of permanganate is standardized by titration with oxalic acid, . To react completely with mol of oxalic acid required 22.69 mL of permanganate solution. The unbalanced chemical equation for the reaction in acidic solution is
The question is incomplete, the complete question is:
A solution of permanganate is standardized by titration with oxalic acid. To react completely with 0.0018 mol of oxalic acid required 22.69 mL of permanganate solution. The unbalanced chemical equation for the reaction in acidic solution is:
[tex]MnO_4^-(aq)+H_2C_2O_4(aq)\stackrel{\mathrm{Acidic}}{\longrightarrow} Mn^{2+}(aq)+CO_2(g)[/tex]
Determine the concentration of the permanganate solution in molarity.
Answer: The molarity of permanganate solution is 0.0317 M
Explanation:
The balanced chemical equation follows:
[tex]2MnO_4^-(aq)+6H^+(aq)+5H_2C_2O_4(aq)\stackrel{\mathrm{Acidic}}{\longrightarrow} 2Mn^{2+}(aq)+8H_2O(l)+10CO_2(g)[/tex]
Given values:
Moles of oxalic acid = 0.0018 moles
By the stoichiometry of the reaction:
If 5 moles of oxalic acid reacts with 2 moles of permanganate solution
So, 0.0018 moles of oxalic acid will react with = [tex]\frac{2}{5}\times 0.0018=0.00072mol[/tex] of permanganate solution
The formula used to calculate molarity:
[tex]\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{ \text{Volume of solution (mL)}}[/tex] .....(1)
Given values:
Moles of permanganate solution = 0.00072 moles
Volume of solution = 22.69 mL
Putting values in equation 1, we get:
[tex]\text{Molarity of permanganate solution}=\frac{0.00072\times 1000}{22.69}\\\\\text{Molarity of permanganate solution}=0.0317M[/tex]
Hence, the molarity of permanganate solution is 0.0317 M
The concentration of the permanganate solution in molarity is 0.0317 M
We'll begin by calculating the number of mole of permanganate needed to react with 0.0018 mole of oxalic acid.
2MnO₄¯(aq) + 5H₂C₂O₄(aq) + 6H⁺(aq) —> 2Mn²⁺(s) + 10CO₂(g) + 8H₂O(l)
From the balanced equation above,
5 moles of H₂C₂O₄ reacted with 2 moles of MnO₄¯
Therefore,
0.0018 mole of H₂C₂O₄ will react with = (0.0018 × 2) / 5 = 0.00072 mole of MnO₄¯
Finally, we shall determine the molarity of the permanganate solution.Mole of MnO₄¯ = 0.00072 mole
Volume = 22.69 mL = 22.69 / 0.02269 L
Molarity of MnO₄¯ =Molarity = mole / Volume
Molarity of MnO₄¯ = 0.00072 / 0.02269
Molarity of MnO₄¯ = 0.0317 MTherefore, the molarity of the permanganate solution is 0.0317 M
Complete question:
A solution of permanganate is standardized by titration with oxalic acid. To react completely with 0.0018 mol of oxalic acid required 22.69 mL of permanganate solution. The unbalanced chemical equation for the reaction in acidic solution is:
MnO₄¯(aq) + H₂C₂O₄(aq) —> Mn²⁺(s) + CO₂(g)
Determine the concentration of the permanganate solution in molarity.
Learn more: https://brainly.com/question/25768579
How many pili are in a bacterial cell
Answer: Bacterial species where observed Typical number on cell Distribution on cell surface
Escherichia coli (common pili or Type 1 fimbriae) 100-200 uniform
Neisseria gonorrhoeae 100-200 uniform
Streptococcus pyogenes (fimbriae plus the M-protein) ? uniform
Pseudomonas aeruginosa 10-20 polar
Explanation:
Pili are structures that extend from the surface of some bacterial cells.
These are hollow, non-helical, filamentous appendages.
Hope it helps you
A peanut was burned in a calorimeter filled with 70g of water. The temperature
increased from 21°C to 87°C. How much heat was released by the peanut. The
specific heat of water is 4.18 J/gºC *
Answer:
[tex]heat = mc \triangle \theta \\ = 70 \times 4.18 \times (87 - 21) \\ = 19311.6 \: joules[/tex]
Calculate the molarity of a solution containing 1.5 moles of NaCl in 0.5 L of solution
Answer:
3 M
Explanation: 1.5mol/.5L = 3M
A mixture containing nitrogen, hydrogen, and iodine established the following equilibrium at 400 °C:2NH3(g) + 3I2(g) ⇌ N2(g) + 6HI(g)Use the information below to calculate Kc for this reaction.N2(g)+3H2(g)⇌2NH3(g) Kc1= 0.50 at 400CH2(g)+I2(g)⇌2HI(g Kc2= 50 at 400°C
Answer: The value of [tex]K_{c}[/tex] for this reaction is 250000.
Explanation:
The given equation is as follows.
[tex]2NH_{3}(g) + 3I_{2}(g) \rightleftharpoons N_{2}(g) + 6HI(g)[/tex]
[tex]N_{2}(g) + 3H_{2}(g) \rightleftharpoons 2NH_{3}(g); K_{c_{1}} = 0.50[/tex] ... (1)
[tex]H_{2}(g) + I_{2}(g) \rightleftharpoons 2HI(g); K_{c_{2}} = 50[/tex] ... (2)
To balance the atoms, multiply equation (2) by 3. Hence, the equation (2) can be re-written as follows.
[tex]3H_{2}(g) + 3I_{2}(g) \rightleftharpoons 6HI(g); K_{c_{2}} = (50)^{3}[/tex] ... (3)
Now, subtract equation (1) from equation (3). So, the equation formed will be as follows.
[tex]3I_{2} - N_{2} \rightleftharpoons 6HI - 2NH_{3}[/tex]
This equation can also be re-written as follows.
[tex]3I_{2} + 2NH_{3} \rightleftharpoons N_{2} + 6HI[/tex]
This equation is similar to the equilibrium equation given to us.
Therefore, during this subtraction the equation constants get divided as follows.
[tex]K^{'}_{c} = \frac{K_{c_{2}}}{K_{c_{1}}}\\= \frac{(50)^{3}}{0.50}\\= 250000[/tex]
Thus, we can conclude that the value of [tex]K_{c}[/tex] for this reaction is 250000.
Give the definition for diffusion. Group of answer choices gas molecules mix equally average distance between collisions gas molecules escape from a container into a vacuum through a small hole gas molecules mix unequally gas molecules spread out in response to a concentration gradient Next
Answer:
gas molecules spread out in response to a concentration gradient.
Explanation:
Diffusion can be defined as the movement of gas molecules from a region of high concentration to a region of lower concentration until an equilibrium is attained or reached. This mixing of gas molecules in the liquid or gaseous state is due to their kinetic energy of random motion i.e without requiring bulk motion.
This ultimately implies that, diffusion is a phenomenon through which gas molecules in either a gaseous or liquid state spread out in response to a concentration gradient, which is simply the difference in concentration of the gases across a space.
In conclusion, increasing the surface area of a gas increases its collision rate and it's considered to be an evolutionary strategy that maximizes the diffusion of gas molecules by catalysing the rate of a gaseous reaction.
Identify each of the following reactions as balanced or unbalanced
Which reactions are you referring to?
Can you add an image please?
or the reactions you are asking about?
A 0.2264 g sample of a pure carbonate, XnCO3(s) , was dissolved in 50.0 mL of 0.1800 M HCl(aq) . The excess HCl(aq) was back titrated with 24.90 mL of 0.0980 M NaOH(aq) . How many moles of HCl react with the carbonate
Answer:
6.56x10⁻³ mol
Explanation:
First we calculate how many HCl moles are there in 50.0 mL of a 0.1800 M solution:
0.1800 M * 50.0 mL = 9.00 mmol HClThen we need to calculate how many HCl moles were in excess, that number is the same as the number of NaOH moles they reacted with:
0.0980 M * 24.90 mL = 2.44 mmol NaOH = 2.44 mmol HClFinally we calculate the difference between the original number of HCl moles and the number remaining after the reaction with XnCO₃:
9.00 mmol - 2.44 mmol = 6.56 mmol6.56 mmol / 1000 = 6.56x10⁻³ molwhat is the relationship between Celsius scale and Kelvin scale of temperature ? very sort answer
Answer:
Celsius + 273 = Kelvin
Explanation:
what is the NGOs location in Nigeria
Is Dioxin chemical ionic or covalent and acidic or basic? Explain
Answer:
Learning Objective Identify element pairs which are likely to form ionic or covalent bonds Key Points Ionic compounds are formed from strong electrostatic interactions between ions, which result in higher melting points and electrical conductivity compared to covalent compounds.Dioxins are a group of highly toxic chemical compounds that are harmful to health. They can cause problems with reproduction, development, and the immune system. They can also disrupt hormones and lead to cancer. Known as persistent environmental pollutants (POPs), dioxins can remain in the environment for many years. Covalent compounds have bonds where electrons are shared between atoms. Due to the sharing of electrons, they exhibit characteristic physical properties that include lower melting points and electrical conductivity compared to ionic compounds. Terms electronegativity: The tendency of an atom or molecule to attract electrons and form bonds. octet rule: Atoms lose, gain, or share electrons in order to have a full valence level of eight electrons. Hydrogen and helium are exceptions because they can hold a maximum of two valence electrons. valence electrons: Electrons in the outermost principal energy (valence) level of an atom that can participate in the formation of chemical bonds with other atoms. Two Classes of Compounds Compounds are defined as substances containing two or more different chemical elements. They have distinct chemical structures characterized by a fixed ratio of atoms held together by chemical bonds. Here, we discuss two classes of compounds based on the bond type that holds the atoms together: ionic and covalent. Covalent Compounds Covalent bonds are characterized by the sharing of electrons between two or more atoms. These bonds mostly occur between nonmetals or between two of the same (or similar) elements.Two atoms with similar electronegativity will not exchange an electron from their outermost shell; the atoms instead share electrons so that their valence electron shell is filled. Examples of compounds that contain only covalent bonds are methane (CH4), carbon monoxide (CO), and iodine monobromide (IBr). Ionic Compounds Ionic bonding occurs when there is a large difference in electronegativity between two atoms. This large difference leads to the loss of an electron from the less electronegative atom and the gain of that electron by the more electronegative atom, resulting in two ions. These oppositely charged ions feel an attraction to each other, and this electrostatic attraction constitutes an ionic bond. Ionic bonding occurs between a nonmetal, which acts as an electron acceptor, and a metal, which acts as an electron donor. Metals have few valence electrons, whereas nonmetals have closer to eight valence electrons; to easily satisfy the octet rule, the nonmetal will accept an electron donated by the metal. More than one electron can be donated and received in an ionic bond. Some examples of compounds with ionic bonding include NaCl, KI, MgCl2.Explanation:
#hopeithelpsstaysafe and keep wellcan you mark me as your brainliest pls?Enter the molecular formula for butane, C4H10
Answer:
C4H10
Explanation:
you already written it :)
A 300 g sample of copper is heated to 285°C and then placed into 1000 g of water at 26.5°C period what was the final temperature of the water?
Answer:
33.4 °C
Explanation:
The final temperature of water will be the equilibrium temperature. This can be obtained as follow:
Mass of copper (M꜀) = 300 g
Initial temperature of copper (T꜀) = 285 °C
Specific heat capacity of copper (C꜀) = 0.385 J/gºC
Mass of water (Mᵥᵥ) = 1000 g
Initial temperature of water (Tᵥᵥ) = 26.5 °C
Specific heat capacity of water (Cᵥᵥ) = 4.184 J/gºC
Equilibrium temperature (Tₑ) =?
Heat lost by copper = Heat gained by water
M꜀C꜀(T꜀ – Tₑ) = MᵥᵥCᵥᵥ(Tₑ – Tᵥᵥ)
300 × 0.385 (285 – Tₑ) = 1000 × 4.184 (Tₑ – 26.5)
115.5(285 – Tₑ) = 4184(Tₑ – 26.5)
Clear the bracket
32917.5 – 115.5Tₑ = 4184Tₑ – 110876
Collect like terms
32917.5 + 110876 = 4184Tₑ + 115.5Tₑ
143793.5 = 4299.5Tₑ
Divide both side by 4299.5
Tₑ = 143793.5 / 4299.5
Tₑ = 33.4 °C
Therefore, the final temperature of water is 33.4 °C.
Explain why the symbol for an atom of the element oxygen and the formula for a molecule of oxygen differ
Answer:
the symbol O represents one molecule of oxygen however oxygen is diatomic when found in nature which is why the formula for the molecule is O2 (sorry i couldnt put the 2 small like its supposed to be but it still represents two molecules of oxygen)
When a liquid sample is taken from sea level to a higher elevation, what happens to the external (atmospheric) pressure on the liquid and the boiling point of the liquid
Answer:
The external atmospheric pressure decreases and so does the boiling point of the liquid.
Explanation:
We know that pressure decreases with height. Thus atmospheric pressure decreases at higher elevation.
The implication of this is that, if I take a liquid from sea level to a higher elevation, the external atmospheric pressure on the liquid will decrease and so does its boiling point.
Hence, the liquid boils at a lower temperature when placed at a higher elevation. For this reason, the boiling point of a liquid is lower on the mountain.
ASAP
A chemical equilibrium between gaseous reactants and products is shown.
N2(g) + 3H2(g) ⇌ 2NH3(g)
How will the reaction be affected if the pressure on the system is increased?
It will shift toward the reactant side as there is lower pressure on the reactant side.
It will shift toward the product side as there is higher pressure on the product side.
It will shift toward the reactant side as there are a greater number of moles of gas on the reactant side.
It will shift toward the product side as there are a fewer number of moles of gas on the product side
The chemical equilibrium is the state at which the rate of reaction is constant. The increase in pressure shifts the reaction towards the product side, as fewer moles of the product are there.
What are the factors affecting the chemical equilibrium?The chemical equilibrium is shifters with the change in the concentration, temperature, pressure, and volume of the reaction.
The increase in the pressure results in more contact between the reactant molecules, as they are more in number and moles in the reaction.
The increased collision of the reactant molecules tried to reach the equilibrium condition, and the increased formation of the product is observed.
Thus, the increase in the pressure shifts the chemical equilibrium towards the product, as there were few moles of the product in the reaction.
Learn more about chemical equilibrium, here:
https://brainly.com/question/4289021
Answer:
its C
Explanation:
just took the test
SCIENCE
11. farmers tend to clear and bum a patch of forest area
Answer:
n8ce question and answer is time taken
[1] Mass of salt (g) 2.005 1.993 [2] Volume of DI water (mL) 49.8 50.0 Mass of DI water (g) [3] Temperature of DI water (°C) 23.4 23.5 [4] Temperature of mixture after dissolution (°C) 20.4 30.9 Temperature difference (°C) -3 7.4 [5] Total mass in reaction (g) 2.1 2.0 Total moles reacted (mol) .026 Total heat of the reaction (cal) [6] Enthalpy of solution ΔHsolution (cal/mol)
The reaction between hydrogen ion and hydroxide ion will be as follows.
so, ratio between hydrogen and hydroxide ions is 1 : 1.
Therefore, moles of = volume × concentration of
=
= 0.06 mol
Similarly, moles of = volume × concentration of
=
= 0.1 mol
Therefore, ratio of moles of hydrogen and hydroxide ions is as follows.
0.06 : 0.1
= 0.6 : 1
As, hydroxide ions are present in excess so, hydrogen ions are the limiting reagent.
Hence, moles of water formed = moles of ions = 0.06 mol.
So, heat released = moles of
= 0.062 × 62.0 kJ/mol
= 3.72 kJ
= 3.72 × 1000 J
= 3720 J
Let T is the initial temperature. So,
Heat released = Heat absorbed by the solution
=
3720 J =
T =
Thus, we can conclude that initial temperature is .
What is the concentration of a solution that has a volume of 2.5 L and contains 660 g of calcium phosphate? (molar mass of calcium phosphate = 310.18 g/mol)
Answer:
0.85 M
Explanation:
Step 1: Given data
Mass of calcium phosphate (m): 660 gVolume of solution: 2.5 LMolar mass of calcium phosphate (M): 310.18 g/molStep 2: Calculate the moles (n) corresponding to 660 g of calcium phosphate (solute)
We will use the following expression.
n = m/M
n = 660 g/(310.18 g/mol) = 2.13 mol
Step 3: Calculate the molar concentration (molarity) of the solution
Molarity is equal to the moles of solute divided by the liters of solution.
M = 2.13 mol/2.5 L = 0.85 M
Which sentence best describes why MnSO4→MnO+SO3 is not a synthesis reaction?
The equation is not balanced.
The reaction has more than one product.
Oxygen is not a reactant in this reaction.
Energy is not a product in this reaction.
Answer:
The reaction has more than one product.
Explanation:
Answer:
The reaction has more than one product.
Explanation:
how do I name cycloalkanes?
Answer:
[tex]{ \tt{aromatic \: alkanes}} \\ \\ { \underline{ \blue{ \tt{becker⚜jnr}}}}[/tex]
1. Determine the number of sides of the cyclic compound.
2. Use IUPAC theory, determine the functional group and its position.
A pattern of stars that has been named is called a constellation. Late at night, Carolyn saw the constellation named Leo, the lion, in the eastern part of the sky. A drawing of Leo is shown below.
Leo
Early the next morning before sunrise, Carolyn saw the same constellation in the western part of the sky. How could she see the same constellation in a different part of the sky?
A.
The stars revolve around the Earth once each month.
B.
The stars appear to move because the Earth rotates on its axis.
C.
There is more than one set of stars in the same pattern as Leo.
D.
The stars move in different directions every night.
Answer:
The correct answers are B. Constellations can be used for navigational purposes, D. Constellations are used by astronomers to locate objects in the night sky., and E. Constellations are used by astronomers to locate objects in the night sky.
Explanation:
1. Make ___________________
Observe an event. State only what we can
________ or ____________.
2. Ask ___________________
Ask a question that helps us find out _______ and _______ the event happened. We must be
able to answer the question with ________, or ________. We may need to __________ our question several times before it is__________.
3. Construct a_____________________
State the answer we think we’ll get when we ask
our question. This is called a
_________________. It’s based on our best
understanding of the event.
4. Test the hypothesis with an
_______________________
Test whether the hypothesis is ___________.
During the investigation, we collect _______ that
answers the testable question we asked.
Answer:
Explanation:
ANCHOR ANCHOR ANCHOR ANCHOR
Metallic Bond
When nitrogen shares electrons with oxygen, what kind of bond is made?
Answer: covalent bonds
Explanation:
The solubility of CaSO4 in pure water at 0oC is 1.09 gram(s) per liter. The value of the solubility product is g
Answer: See image attached!
Good luck with your future exams!
The value of the solubility of product for CaSO₄ in pure water at 0 °C is 1.1881
What is solubility of product?The solubility of product (Ksp) is defined as the concentration of products raised to their coefficient coefficients. This is illustrated below:
mA <=> nC + eD
Ksp = [C]^n × [D]^e
With the above information in mind, we can obtain the solubility of the product. This is illustrated below:
Dissociation equationCaSO₄(aq) → Ca²⁺(aq) + SO₄²⁻(aq)
From the balanced equation above,
1 mole of CaSO₄ contains 1 mole of Ca²⁺ and 1 mole of SO₄²⁻
How to determine the concentration of Ca²⁺ and SO₄²⁻From the balanced equation above,
1 mole of CaSO₄ contains 1 mole of Ca²⁺ and 1 mole of SO₄²⁻
Therefore,
1.09 g/L of CaSO₄ will also contain
1.09 g/L of Ca²⁺1.09 g/L of SO₄²⁻ How to determine the solubility of product Concentration of Ca²⁺ = 1.09 g/L Concentration of SO₄²⁻ = 1.09 g/L Solubility of product (Ksp) =?CaSO₄(aq) → Ca²⁺(aq) + SO₄²⁻(aq)
Ksp = [Ca²⁺] × [SO₄²⁻]
Ksp = 1.09 × 1.09
Ksp = 1.1881
Learn more about solubility of product:
https://brainly.com/question/4530083
