Question 35

Question

Question 35
Atoms and molecules are constantly in motion. The more kinetic energy atoms or molecules have, the faster they move about. In which state of matter do the atoms and molecules have the least kinetic energy?

a
solid
 b
gas
 c
liquid
 d
not enough information to determine
Question 36
The chemical equation for the reaction between magnesium (Mg) and hydrochloric acid (HCl) is shown.

Mg + 2HCl → MgCl2 + H2

Fiona weighs the magnesium and hydrochloric acid before the reaction and finds a total mass of 55 grams. After the reaction, she measures the mass of the products, magnesium chloride (MgCl2) and hydrogen (H2), and finds a total mass of 55 grams again. Does Fiona's data support the law of conservation of matter, and why?

a
No, because the mass of the reactants is the same as the mass of the products in her data.
 b
Yes, because the mass of the reactants is lower than the mass of the products in her data.
 c
Yes, because the mass of the reactants is the same as the mass of the products in her data.
 d
No, because the mass of the reactants is lower than the mass of the products in her data.
Question 37
A chemist is trying to get two substances to react, but he is unsuccessful. He knows that the two substances should react with one another.  Which of the following could he do to possibly get the substances to react? (Select all that apply)

a
decrease the concentration of one of the substances
 b
heat the substances
 c
crush up one of the substances
 d
increase the concentration of one of the substances
 e
cool the substances
Question 38
Match the missing coefficient to the correct number of molecules so that the equation adheres to the conservation of mass.

(X)N2 + (Y)H2 → (Z)NH3

Column A
1.
X:
X
2.
Y:
Y
3.
Z:
Z
Column B
a.2
b.1
c.3

GPT-4o mini · Answer

**Question 35:** In which state of matter do the atoms and molecules have the least kinetic energy? a solid **Explanation:** In solids, atoms and molecules are closely packed together and can only vibrate in place, resulting in the least amount of kinetic energy compared to liquids and gases, where molecules can move more freely. --- **Question 36:** Does Fiona's data support the law of conservation of matter, and why? c Yes, because the mass of the reactants is the same as the mass of the products in her data. **Explanation:** The law of conservation of matter states that matter cannot be created or destroyed in a chemical reaction. Since the total mass of the reactants (55 grams) is equal to the total mass of the products (55 grams), Fiona’s data supports this law. --- **Question 37:** Which of the following could he do to possibly get the substances to react? (Select all that apply) b heat the substances c crush up one of the substances d increase the concentration of one of the substances **Explanation:** Heating the substances can increase the kinetic energy of the molecules, leading to a higher frequency of collisions. Crushing a substance increases its surface area, allowing for greater interaction between the reactants. Increasing the concentration of a reactant increases the number of particles available to collide and react. --- **Question 38:** Match the missing coefficient to the correct number of molecules so that the equation adheres to the conservation of mass. N2 + (Y)H2 → (Z)NH3 1. X: 1 2. Y: 3 3. Z: 2 **Explanation:** The balanced equation would be: 1 N2 + 3 H2 → 2 NH3. Thus, X = 1, Y = 3, and Z = 2.