Question

Q1: What is the definition of isotopes?

A: Two elements that have same number of electrons, protons and neutrons B: Two elements that have different number of electrons C: Two elements that have identical number of protons, but different number of neutrons D: Three elements that have identical number of protons

Q2: Which compound has the highest boiling point in this series?

A: Water B: Ethylene C: Caron Tetrachloride D: Ethyl Alcohol

Q3: What is the definition of mole of a compound?

A: Molecular weight of the compound in gram B: Divide the molecular weight of the compound by 1000 C: Divide the molecular weight of the compound by 100 D: Divide the molecular weight of the compound by the atomic weight of one of the constituents

Q4: Which one of the following is a pure substance?

A: Chlorophyll B: Milk C: Cement D: Air

Q5: Which of the following solution is the most concentrated?

A: 0.1 molar KCl in 100 mL water B: 1.0 molar NaCl in 100 mL water C: 1.0 molar NaCl in 100 mL water and 100 ml DMSO D: 1. 0 molar NaCl in 100 mL water and 1 ml DMSO

Q6: What is the oxidation state of Al in NaAlO2?

A: +1 B: + 2 C: +3 D: -4

Q7: Which one of the following behaves like a non-electrolyte in water solution?

A: Calcium oxide B: Carbon tetrachloride C: MgBr2 D: NH3

Q8: Which one has the highest lattice energy?

A: NaI B: NaF C: NaCl D: NaBr

Answer 1

Ans(1) Option C

Two elements that have identical number of proton but different number of neutrons.

And(2) Option A

Water 100' > ethyl alcohol 78.5' > carbon tetrachloride 76.7' > Ethylene -103'.

And(3) Option A

Molecular weight of the compound in grams.

And(4) Option C

Cement is a mixture because it is composed of different types of compound particles. Each of the component of the concrete by themselves would be pure substances. For example a sample of just calcium oxide would be a pure substance because the particle in the sample would all be identical calcium oxide compounds.