What is the heat capacity of 170 g of liquid water?

The specific heat capacity of water (which is defined as the amount of heat required to raise the temperature of one gram of water by 1 degree kelvin) is given as 4.1813J/gK (at 25°C).

Therefore, to get the heat capacity of a certain mass (in grams), we just have to multiply this mass by the specific heat capacity of water as follows:
heat capacity of 170 g = 170 * 4.1813 = 710.821 J/K

The air is going to come out because of the low pressure.