Question

At STP, adding salt to a 200 mL sample of water produces a saturated 1.7 M solution. How many grams of salt (NaCl) must be added to 200 mL to produce this solution?

Answer 1

Answer:

$m_{NaCl}=19.9gNaCl$

Explanation:

Hello!

In this case, since the formula for the calculation of molarity is:

$M=\frac{n}{V}$

Whereas we can compute the moles of the solute as shown below, making sure the volume is in liters:

$n=M*V$

Thus, by plugging in we obtain:

$n=0.200L*1.70mol/L=0.170molNaCl$

Next, since the molar mass of NaCl is 58.44 g/mol, we obtain the following mass:

$m_{NaCl}=0.170molNaCl*\frac{58.44gNaCl}{1molNaCl}\\\\m_{NaCl}=19.9gNaCl$

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