Chemistry Past Questions And Answers
..............................P....Q......R.......S Proton..............13....16....17.....19 Electron............13....16....17.....19 Neutron.............14....16....35.....20 Which of the four atoms P,q,R and in S in the above data can be described by the following properties relative atomic mass is greater than 30 but less than 40; it has an odd atomic number and forms a unipositive ion in solution?
- A. P
- B. Q
- C. R
- D. S
The flame used by welders in cutting metals is
- A) butane gas flame
- B) acetylene-hydrogen flame
- C) kerosene flame
- D) oxy-acetylene flame
What mass of water is produced when 8.0g of hydrogen reacts with excess oxygen?
- A. 8.0g
- B. 16.0g
- C. 36.0g
- D. 72.0g
The periodic classification of the elements is an arrangement of the elements in order of their
- A) atomic weights
- B) isotopic weights
- C) molecular weights
- D) atomic numbers
A concentrated solution containing H+, Cu2+, OH- and Cl- was electrolyzed using platinum electrodes. The ion that will be discharged at the cathode is
- A. Cu2+
- B. Cl-
- C. H+
- D. OH-
In the laboratory preparation of ethyl ethanoate, the water present in the mixture is removed using a solution of
- A) an hydrous CaCl4
- B) concentrated NaCO4
- C) dilute NaOH
- D) concentrated H4SO4
When water drops are added to calcium carbide in a container and the gas produced is passed through a jet and lighted, the resultant flame is called an?
- A. Oxyethene
- B. Oxyhydrocarbon flame
- C. Oxyacetylene flame
- D. Oxymethane flame
The reactions ethyne are mainly
- A. substitution reactions
- B. addition reactions
- C. addition polymerization
- D. catalytic hydrogenation
The oxidation state of P in H\(_2\)P\(_2\)O\(_7^{2-}\) is _______
- A) -3
- B) +3
- C) +1
- D) +5
A gas occupies 30.0dm3 at S.T.P. What volume would it occupy at 91°C and 380mmHg? Options
- A) 20.0dm3
- B) 40.0dm3
- C) 60.0dm3
- D) 80.0dm3