Molarity and Dilution How many moles are needed in a 100. mL solution of a 0.10M CuSO4 5H2O solution?

The moles needed are 0.01.

Explanation:

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

where,

n = moles of solute = ?  

= volume of solution in ml  

Now put all the given values in the formula of molarity, we get

Therefore, the moles needed are 0.01.

given:

mass of na = 115 g

excess cl2

to determine:

mass of nacl produced

explanation:

given reaction is-

2na(s) + cl2(g) → 2nacl(s)

since cl2 is in excess, na will be the limiting reagent

as per the reaction stoichiometry na: nacl = 1: 1

i.e. moles of na reacted = moles of nacl formed

now, # moles of na = mass of na/atomic mass

                                  = 115 g/23 g.mol-1 = 5 moles

therefore, moles of nacl = 5

molar mass of nacl = 58 g/mol

mass of nacl = 5 moles * 58 g.mol-1 = 290 g

ans: amount of nacl produced = 290 g