Students measure the weight of some baking soda, a solid. They also measure the weight of some vinegar, a liquid. They mix the substances together and many bubbles appear on the surface of the new liquid. They measure the weight of this new liquid and it is less than the sum of the weights of the baking soda and vinegar before mixing. Why is the weight of the new liquid less than the sum of the weights before mixing? Answer options with 4 options A. because the solid melted B. because the solid dissolved C. because a gas formed and escaped D. because a liquid weighs less than a solid

answer: - first one is the correct answer. .

explanations: - potassium sulfide is and cobalt(ii) chloride is .

charge on k is +1, charge on s is -2, charge on co is +2 and charge on cl is -1.

in a double replacement reaction the ion exchange takes place. in general the reaction looks like:

if one of the product is insoluble as per solubility rules then a precipitate of it is formed.

when we mix the aqueous solutions of potassium sulfide and cobalt(ii) chloride then chloride ion goes with potassium ion and sulfide ion goes with cobalt ion and the balanced equation is written as:

k and cl has equal charges, similarly co and s has equal charges and hence no subscripts are used for the product side.

as per the solubility rules, cos is insoluble and so it's precipitate is formed.

looking at the given choices, first choice is correct.