How many grams of salt per 1000. g of ice is needed to make it liquid at –7.0°C?

Question

How many grams of salt per 1000. g of ice is needed to make it liquid at –7.0°C?

Note:

One mole of any particle dissolved in 1000. g of water lowers the freezing point of the water by 1.86°C.

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Answer 1

First, let's determine how many moles of particles will be needed to lower the freezing point of water by 7° C. This would be 7/1.86 = 3.76 moles of particles.

As NaCl dissociates in water to produce 2 particles, we only need half as many moles of NaCl or

3.76 /2 = 1.88 moles of NaCl needed.

We need to convert 1.88 moles NaCl to grams by multiplying the formula mass of NaCl by 1.88.

58.44 g/mole x 1.88 moles = 109.9 g NaCl needed.

please check math.