Question

4. The charge most commonly found on Ca is (insert number).
Answer 1:
2 (INCORRECT)

6. One reagent bottle on the shelf in a laboratory is labeled 12M H2SO4 and another is labeled 12M HCl, which statement is true?
a. There are more grams of H2SO4 in 100 mL of 12 M H2SO4 compared to the grams of HCl in 100 mL of 12 M HCl.

b. (WRONG) There are fewer grams of H2SO4 in 100 mL of 12 M H2SO4 compared to the grams of HCl in 100 mL of 12 M HCl.

c. There are equal grams of H2SO4 in 100 mL of 12 M H2SO4 compared to the grams of HCl in 100 mL of 12 M HCl.

9. For a 2.5 M solution of Mg(NO3)2, the concentration of the cation species is  
______ M and the concentration of the anion species is ______ M.
Answer 1:
1 (Incorrect)
Answer 2:
2 (Incorrect)

12. If 0.015 mg Pb2+ were added to enough water to make exactly 1 L of solution, the solution would be ____ in Pb2+
a. 7.2x10^(-3)
b. 1.5x10^(-5)
c. 7.2x10^(-8)
d. 1.5x10^(-8)
e. 7.2x10^(-5)
f. 7.2x10^3
g. 0.015 M (Incorrect)

14. Which one of the following ions is not in Evian
a. Ca2+
b. Mg2+
c. HCO3- (Incorrect)
d. SO42-
e. NO2-
f. NO3-

16. Which one of the following is not a true statement about water purification.
a. water can be desalinated by reverse osmosis
b. water can be desalinated by distillation (Incorrect)
c. water can be purified by chlorination
d. water can be purified by nitration
e. water can be purified by adding aluminum sulfate
f. water can be purified by addition calcium hydroxide

30. In the following equation which one of the compounds is acting as an acid H2(SO4) + H2O --> HSO4- + H3O+
a. H2O (Incorrect)
b. H2SO4
c. H3O+
d. HSO4-
e. none of the above

31. Which one of the following is not a source of acidic rain.
a. H2SO4
b. HNO3
c. H2CO3 (Incorrect)
d. CO2
e. NH3

38. If the hydroxide concentration is 1x10^(-9) then the hydronium ion concentration is 1x10 ____
Answer 1: 5 (Incorrect)

Answer 1

Ans :

The charge most commonly found on Ca is +2.

It forms the compounds such as CaCl2 , Ca(OH)2 etc , where it has the charge of +2 in the compound.