A compound contains 40.0% carbon, 6.7% hydrogen, and 53.3% oxygen. If its relative molecular mass is 180, what is its molecular formula? (C=12, H=1, O=16)

In the electrolysis of CuSO_4 solution using copper electrodes, if 0.5 faraday of electricity is passed, what is the change in mass of the cathode? (Cu=63.5)

A radioactive isotope has a half-life of 10 hours. What fraction of the original atoms remains after 30 hours?

For the reaction 2SO_2(g) + O_2(g) \rightleftharpoons 2SO_3(g) \Delta H = -197 kJ mol^{-1} , which of the following conditions will favor the formation of SO_3 ?

The pH of a 0.01 mol dm⁻³ solution of a weak acid is 4. What is its dissociation constant?

If the standard electrode potentials are E^0_{Zn^{2+}/Zn} = -0.76 V and E^0_{Cu^{2+}/Cu} = +0.34 V , what is the EMF of the cell?

In the reaction 2H_2O_2(aq) \rightarrow 2H_2O(l) + O_2(g) , the initial rate of decomposition of H_2O_2 was 1.0 \times 10^{-4} mol dm^{-3} s^{-1} . What is the initial rate of formation of O_2 ?

A gas occupies 300 cm³ at 27°C and 700 mmHg. What volume will it occupy at 57°C and 840 mmHg?

The heat of combustion of carbon to CO_2 is -394 kJ/mol. The heat released when 6.0g of carbon is completely burnt in oxygen is: (C=12)

Which of the following 0.1 M solutions will have the lowest pH?

The IUPAC name for CH_3CH_2C(CH_3)=CH_2 is:

In the laboratory preparation of ethyl ethanoate, concentrated H_2SO_4 serves as:

Which of the following represents the correct order of increasing boiling points?

The hybridization of the carbon atoms in ethyne is:

A compound that gives a positive iodoform test is:

In the contact process for the manufacture of sulphuric acid, the catalyst used is:

The polymer formed from the monomer CH_2=CHCl is:

The number of isomers of C_4H_8 that are alkenes is:

In the extraction of iron, the function of limestone in the blast furnace is to:

A solution of pH 4 is diluted 100 times. The pH of the resulting solution is approximately:

The volume of 0.5 M H_2SO_4 required to neutralize 25 cm³ of 0.2 M NaOH is:

The oxidation number of chromium in K_2Cr_2O_7 is:

Which of the following gases will diffuse fastest under the same conditions?

The bond angle in H_2O is 104.5° while in CH_4 it is 109.5°. This difference is due to:

The empirical formula of a compound is CH_2O . If its vapour density is 30, its molecular formula is: (C=12, H=1, O=16)

In the reaction Fe_2O_3 + 3CO \rightarrow 2Fe + 3CO_2 , the substance that is reduced is:

Which of the following salts will hydrolyze to give an alkaline solution?

The number of faradays required to discharge 2 moles of Ca^{2+} ions is:

A catalyst affects the rate of a chemical reaction by: