Reference no: EM131522560

1. A solution containing only Naci and water is evaporated to dryness and the residue weights 2.55g. If 55.6 of the solution was taken, what is the mass percent NAci in the orginal solution. The density of the solution is 1.22g.ml

a. 4.59 x10^-2%

b. 4.59%

C. 5.60%

d. 5.65%

E. 21.8%

2. Balance the following equation using the smallest set of whole numbers, then add together the coefficients, Don't forget to count coefficients of one. _____AI+ _____H2SO4à AI2 (SO4)3 +_____H2. The sum of the coefficients is

A.3

B.5

C.6

D.9

E.12

3. Metals react with oxygen to give oxides with the general formula MxOy. What is a balanced chemical equation for the reaction of manganese to yield manganese (VII) oxide?

a. Mn +O2àMn2O7

b. 2 Mn+7 O à Mn2O7

c. 4 Mn + 7 02 à2 mn2o7

d. 7mn + o2 à Mn7o2

e. 7 Mn + o2à Mn7o2