Chemical Questions

Question 12.

12. Regarding the acid-base neutralization reaction

Mg(OH)2 (aq) + 2 HNO3 (aq) ---» 2 H2O (l) + Mg(NO3)2 (aq),

which of the following statements is true? (Points : 5)

Mg(OH)2 is the acid and HNO3 is the salt

Mg(OH)2 is the base and H2O is the salt

HNO3 is the base and Mg(NO3)2 is the salt

HNO3 is the acid and Mg(NO3)2 is the salt

Question 13.

13. In the combustion reaction shown below, 26.0 g of C₂H_{2 (g)}was burned, and 72.4 g of CO_{2 (g)} was produced. Calculate the percent yield.

2 C₂H_{2 (g)}+ 5 O_{2 (g)}→ 4 CO_{2 (g)} + 2 H₂O_(g)

(Points : 5)

100%

88%

82.3%

86.5%

Question 14.

14. Which of the following statements is true? (Points : 5)

Real gases occupy no space at all.

Ideal gases exist in nature.

Real gas molecules have absolutely no attractive forces between them.

Collisions between real gas molecules are mostly, but not always entirely, elastic.

Question 15.

15. In the acid-base neutralization reaction Pb(NO3)2 (aq) + 2 KI (aq) ---» 2 KNO3 (aq) + PbI2 (s), what are the spectator ions? (Points : 5)

Pb +2 and NO3 -1

Pb+2 and I -1

K +1 and I -1

K +1 and NO3 -1

Question 16.

16. In a net ionic equation, ionic charges are not written or shown for __________. (Points : 5)

Spectator ions

Oxidizing agents

Reducing agents

Precipitates

Question 17.

17. In the reaction below, which substance gains electrons?

2 Fe₂O₃(s)+ 3 C_(s)→ 4 Fe_(s) + 3 CO_{2 (g)}

(Points : 5)

This reaction does not contain any elements which gain electrons.

Question 18.

18. In the reaction below, which substance is the reducing agent?

2 Fe₂O₃(s)+ 3 C_(s)→ 4 Fe_(s) + 3 CO_{2 (g)}

(Points : 5)

Fe₂O₃

CO₂

Question 19.

19. After four half-lives, what percentage of the original radioactive sample remains? (Points : 5)

25%

0.4%

6.25%

40%

Question 20.

20. 25 mL of 0.80 M HCl was titrated with NaOH. If 37.5 mL of NaOH were required to reach the endpoint, what was the molarity of the NaOH? (Points : 5)

1172 M

750 M

1.2 M

0.53 M

12 years ago

Report issue

Tests Solution

NOT RATED

Purchase the answer to view it

tests_solution.pdf