What happens to the freezing point if the specific gravity of calcium chloride brine is increased from 1.29 to 1.30?

When the specific gravity of calcium chloride brine is increased, it indicates that the concentration of the brine solution is also increasing. Calcium chloride, when dissolved in water, lowers the freezing point of the solution due to the colligative properties of the solute, specifically freezing point depression.

As the specific gravity increases from 1.29 to 1.30, this implies a higher concentration of calcium chloride in the brine. The increase in concentration means that the solution can impede the formation of ice more effectively, leading to an even lower freezing point compared to the original concentration. In this context, the freezing point of the calcium chloride brine will lower as the specific gravity increases, confirming that a higher concentration allows it to remain liquid at lower temperatures. Therefore, the correct conclusion is that the freezing point lowers.