Ask a New Question
Menu

26. 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
crush up one of the substances
c
cool the substances
d
heat the substances
e
increase the concentration of one of the substances

27. Match the following equations to the type of reaction.

Column A
1. Synthesis
2.Single replacement
3. Combustion
4. Double displacement
5. Decomposition
Column B
a. 2 NaCl + Br2 → 2 NaBr2 + Cl2
b. 2 H2O → 2 H2 + O2
c. Na + Cl → NaCl
d. MgBr2 + 2 NaCl → MgCl2 + 2 NaBr
e. C3H8 + 5 O2 → 3 CO2 + 4 H2O

28. An isotope of the element nitrogen has 7 protons and 9 neutrons. What is the name of the isotope?

a
Nitrogen-7
b
Nitrogen-16
c
Nitrogen-9
d
Nitrogen-14

29. Look at the following equation.
________ Fe + ________ Cl2 → ________ FeCl3

In order to follow the law of conservation of mass, this equation must have which set of coefficients, in order from left to right?

1 answer

26. To possibly get the substances to react, the chemist could:

Select all that apply:

  • b crush up one of the substances
  • d heat the substances
  • e increase the concentration of one of the substances

Crushing substances increases the surface area, heat can increase reaction rates, and increasing concentration can lead to more collisions between reactant particles.

27. Match the following equations to the type of reaction:

Column A

  1. Synthesis
  2. Single replacement
  3. Combustion
  4. Double displacement
  5. Decomposition

Column B a. 2 NaCl + Br2 → 2 NaBr + Cl2 (2. Single replacement)
b. 2 H2O → 2 H2 + O2 (5. Decomposition)
c. Na + Cl → NaCl (1. Synthesis)
d. MgBr2 + 2 NaCl → MgCl2 + 2 NaBr (4. Double displacement)
e. C3H8 + 5 O2 → 3 CO2 + 4 H2O (3. Combustion)

28. The name of the isotope of nitrogen with 7 protons and 9 neutrons is:

b Nitrogen-16

(The number of nucleons is the sum of protons and neutrons, so 7 protons + 9 neutrons = 16 nucleons.)

29. To balance the equation \( ______ \text{Fe} + ______ \text{Cl2} → ______ \text{FeCl3} \):

The balanced equation is:

4 Fe + 3 Cl2 → 4 FeCl3

Therefore, the set of coefficients, in order from left to right, is: 4, 3, 4.