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prepare 1L of a 0.5 M solution of sodium chloride. Quiz Solutions C 0 O moodle.h

ID: 588906 • Letter: P

Question

prepare 1L of a 0.5 M solution of sodium chloride. Quiz Solutions C 0 O moodle.harrisburgu.edu/mod/quiz/attempt.php?attempt-166776 Question 2 Not yet answered mass of sodium chloride do you need? Report your answer (only the Points out of 2.00 P Flag question You would like to prepare 1L of a 0.5 M solution of sodium chloride. What numerical portion!) in grams to 2 significant figures. Answer What is the molar mass of magnesium sulfate heptahydrate? Report only the numerical portion of your answer, to 4 significant figures Question 3 Not yet a Points out of 2.00 P Flag question Answer: Question 4 Which of the following is an Erlenmeyer flask? Not yet answered

Explanation / Answer

1)

1. Calculate the molar mass of sodium chloride.

The molar mass of Na is 22.99 g/mol and the molar mass of chlorine is 35.45 g/mol

The molar mass of NaCl = 22.99 g/mol + 35.45 g/mol = 58.44 g/mol

2. Calculate the mol of NaCl need to prepare 1.00 L of a 0.50 M solution.

Molarity (M) = Number of Moles of Solute/Solution Volume (Liter/s)

Number of moles of NaCl = Molarity of NaCl x Solution Volume (Liter/s)

Number of moles of NaCl = 0.50M/1L = 0.5 moles

3. Calculate the mass of NaCl needed to prepare 1.00 L of a 0.50 M solution.

The mass of NaCl = Number of moles of NaCl x molar mass of NaCl

                                = 0.5 moles x 58.44 g/mol

= 29.22 g

Answer 29

3)

Magnesium sulfate heptahydrate MgSO4.7H2O

Molar Mass of

Mg = 24.305 g/mol

S = 32.06 g/mol

O = 16.0 g/mol

H = 1.0 g/mol

Multiply the total no of each atom by their molar mass

MgSO4.7H2O has 1 Mg, 1 S, 11 O, 14 H

Molar mass of MgSO4.7H2O = 1(24.305) + 1(32.06) +11(16) + 14(1) = 246.36 g/mol

Answer 246.4 g/mol