A) Suppose you separate a 3.02 g mixture of sand and salt. You recover 1.43 g of salt and 1.41 g of sand. What is the percent recovery of the mixture? B) Suppose you separate a 3.02 g mixture of sand and salt. You recover 1.43 g of salt and 1.41 g of sand. What is the percent recovery of the mixture?
C) Calculate the percent by mass of a solution made from 15 g NaCl (the solute) and 69 g water.
D) What percent of 73.0 g is 26.1 g?

A-B) 94 %.

C) 17.9 %.

D) 35.8 %.

Explanation:

Hello!

A-B) In this case, since the total mass of the mixture is 3.02 g and 1.43g+1.41g=2.84 g are recovered in total, we can compute the percent recovery as shown below:

C) Here, since the solution is made up of NaCl and water, we can say that the mass of the solution is 15g+69g=84g; thus, the percent by mass would be:

D) In this case, we simply divide 26.1 g by 73.0 g in order to obtain the percent:

Best regards!

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"