7) Ice and salt mixture is used as a freezing agent by manual ice-cream makers.

7) Ice and salt mixture is used as a freezing agent by manual ice-cream makers.  

 Ans: In manual ice-cream making a mixture of salt and ice is always used because salt has capacity to reduce the temperature of ice by decreasing its freezing point. That’s why ice and salt mixture is used as freezing agent in manual ice cream making.