1. explain how you would make 100 ml of a 2.0% (w/v) solution of sodium chloride? 2. how many grams of magnesium sulfate are required to make 250 ml of a 1.6% mgso4 (m/v) solution? 3. a solution contains 2.7 g of cuso4 in 75 ml of solution. what is the percent (mass/volume) of the solution?

1.

Percent (mass/volume) of the solution = (mass of the solute / volume of the solution) x 100

Given, percent of NaCl (m/v) solution = 2.0 %

Volume of solution = 100 ml

Plugging in the numbers in the formula we get,

2.0 = (mass of NaCl/ 100) x 100

Mass of NaCl = (2.0 x 100)/100 = 2 g

So we would dissolve 2g NaCl(s) in 100 ml water to form a 2.0% NaCl solution.

2.

Percent (mass/volume) of the solution = (mass of the solute / volume of the solution) x 100

Given, percent of MgSO₄ (m/v) solution = 1.6%

Volume of solution = 250 ml

Plugging in the numbers in the formula we get,

1.6 = (mass of MgSO₄/ 250) x 100

Mass of MgSO₄ = (1.6 x 250)/100 = 4 g

3.

Percent (mass/volume) of the solution = (mass of the solute / volume of the solution) x 100

Given, mass of CuSO₄ = 2.7 g

Volume of solution = 75 ml

Percent (mass/volume) of the solution = (2.7 g/ 75 ml) x 100 = 3.6%

in 1783 cavendish was working with his hydrogen gas and found that when he burned it and condensed the vapor it was water. this was very significant since it disproved the greek theory of elements completely since water was not a simple substance but the product of two gases. it was lavoisier who hearing of the experiment gave cavendish's gas the name hydrogen ("water-producer") and added that hydrogen burned by combining with oxygen and that water was a hydrogen-oxygen combination.

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