Student X titrated 25 cm\(^{3}\) of Na\(_{2}\)CO\(^{3}\) with 0.1 mol dm\(^{-3}\) HCI, using methyl orange as indicator. Student Y carried out the same exercise but used phenolphthalein as an indicator. Which of the following statements about the titration is true?

A. hydrogen chloride gas was released in the reactions in both titrations

B. the titer values obtained from the titration are equal

C. the tirer value obtained by X is twice that of Y

D. the titer value obtained by Y is twice that of X

What is the concentration of a solution which contains 0.28g of potassium hydroxide in 100 cm\(^{3}\) of solution [KOH = 56]

A. 0.01 mol dm\(^{-3}\)

B. 0.05 mol dm\(^{-3}\)

C. 0.10 mol dm\(^{-3}\)

D. 0.50 mol dm\(^{-3}\)

What is the empirical formula of a hydrocarbon containing 0.160 moles of carbon and 0.640 moles of hydrogen

A. CH\(_{2}\)

B. CH\(_{3}\)

C. CH\(_{4}\)

D. C\(_{2}\)H\(_{4}\)

Which of the following species has the largest ionic radius

A. S\(^{2-}\)

B. K\(^{+}\)

C. CI\(^{-}\)

D. Ca\(^{2+}\)

Which of the following statements is correct about ionization energy? It

A. decreases across the periods

B. results in the formation of an anion

C. causes Metalic nuclei to disintegrate

D. decreases down the group

Potassium trioxonitrate (V) can be obtained from its solution by----------

A. distillation

B. evapoartion

C. crystallization

D. filtration

An element, Q, contains 69% of\(^{63}\)Q and 31% of \(^{65}\)Q. What is the relative atomic mass of Q?

A. 63.0

B. 63.6

C. 65.0

D. 69.0

The following ions have the same electron configuration except \(_{8}\)O, \(_{12}\)Mg, \(_{13}\)AI, \(_{17}\)CI

A. CI\(^{-}\)

B. O\(^{2-}\)

C. Mg\(^{2+}\)

D. AI\(^{3+}\)

The region around the nucleus where electrons can be located is called?

A. a spectra

B. an orbital

C. a quanta

D. a field

Protons and electrons are called fundamental particles because they----------

A. are indivisible

B. have different charges

C. are the lightest particles

D. are found in all matter