Chemistry Questions and Answers

molar mass of water [7H\(_2\)O] = 7[ 2 * 1 + 16] → 7 * 18 = 126g/mol

molar mass of ZnSO\(_4\).7H\(_2\)O = [65 * 1] + [32 * 1] + [16 * 4] + 7[ 2 * 1 + 16] 

→ 65 + 32 + 64 + 126 = 287g/mol

percentage of water of crystallization = \(\frac{mass of water of crystallization}{mass of hydrated compound} * 100%\)

→ \(\frac{126}{287} * 100\) = 43.9

≈ 44%

Freezing is a physical change. It involves a liquid changing states to a solid. Thus, freezing a substance will not change its chemical identity, but its state.

Sulfur is insoluble in water but sugar is soluble.

Hence; dissolution of sugar to have sulfur as the only insoluble solid.

Filtration: The filtrate is the liquid that passes through the filtration filter. Meanwhile, the residue is the solid that remains on the filtration filter.

Evaporation: water as part of the filtrate changes into a gas to leave sugar as residue.

The choice of straight hydrocarbon chains primarily serves the purpose of enhancing the biodegradability of the detergent, making it less harmful to the environment once it is washed away.Since unbranched (i.e., straight) chains are more prone to attack by bacteria, therefore in most of the detergents used these days, the branching is kept to be minimum so that the detergents become easily biodegradable.

Polyvinyl chloride is used in the production of pipes. Polyvinyl chloride (PVC) is an odorless and solid plastic. It is most commonly white but can also be colorless or amber. It can also come in the form of white powder or pellets. PVC is made from vinyl chloride. The chemical formula for vinyl chloride is \(C_2H_3Cl\)