Unit 7: #19-25

Question 1

19a. Find the empirical formula.
7.20g C, 1.20g H, 9.60g O

Answer 1

CH2 O

Question 2

19b. If the molar mass is 240g, find the molecular formula of CH2 O

Answer 2

C8 H16 O8

Question 3

21a. Write the balanced equation of the reaction in 20. Make sure it is balanced.

Answer 3

CD3 + DB2 + BAC -> C2 D4 + AB3

Question 4

21b. Where are the reactants in an equation?

Answer 4

Left

Question 5

22a. Balance the following equation.
*AgNO3 + CaCl2 -> AgCl + Ca(NO3)2

Answer 5

2, 1, 2, 1

Question 6

22b. C2 H6 + O2 -> CH3 COOH + H2 O

Answer 6

2, 3, 2, 2

Question 7

22c. HCl + Ba(OH)2 -> BaCl2 + H2 O

Answer 7

2, 1, 1, 2

Question 8

22d. Na + H2 O -> NaOH + H2

Answer 8

2, 2, 2, 1

Question 9

22e. When solid sodium chlorite is strongly heated in a flame it forms oxygen gas and solid sodium chloride.

Answer 9

2NaCl3(s) -> 2NaCl(s) + 3O2(g)

Question 10

22f. Zinc and lead (II) nitrate solution react to form zinc nitrate solution and lead.

Answer 10

Zn(s) + Pb(NO3)2(aq) -> Zn(NO3)

Question 11

23a. Classify MnI2 -> Mn + I2

Answer 11

decomposition

Question 12

23b. Classify C2 H5 OH + 3O2 -> 2CO2 + 3H2 O

Answer 12

combustion

Question 13

23c. Classify CaCl2 + Na2 CO3 -> CaCO3 + 2NaCl

Answer 13

double replacement

Question 14

23d. Classify CO + Cl2 -> COCl2

Answer 14

synthesis

Question 15

23e. Classify Zn + 2HCl4 -> H2 + ZnCl2

Answer 15

single replacement

Question 16

24a. Is decomposition endothermic or exothermic?

Answer 16

endothermic

Question 17

24b. Is combustion endothermic or exothermic?

Answer 17

exothermic

Question 18

24c. Is double replacement endothermic or exothermic?

Answer 18

endothermic

Question 19

24d. Is synthesis endothermic or exothermic?

Answer 19

exothermic

Question 20

24e. Is single replacement endothermic or exothermic?

Answer 20

exothermic

Question 21

25. Draw an energy bar chart for a decomposition reaction.

Answer 21

Eth and Ech start with 2,
2 are added to Eth,
2 Eth are moved to Ech