Lecturer Chemistry Past Paper 22-10-2009 by SPSC

Q31: Who succeeded Siraj-ud-Daula as Nawab of Bengal after the Battle of Plassey?

پلاسی کی لڑائی کے بعد بنگال کے نواب کے طور پر سراج الدولا کو کس نے کامیاب کیا؟

Aliwardi Khan

Mir Qasim

Mir Jafar

None of these

Q32: Which of the following is completely amorphous?

مندرجہ ذیل میں سے کون سا مکمل طور پر بے ساختہ ہے؟

Abestose

Glass fiber

Wool

None of these

Q33: When the following reaction is properly balanced, the number of moles of O2 will be _____? C6H14 + O2 → CO2 + H2O

38 miles

19 moles

13 moles

None of these

Explanation

Balanced Equation: $2 C_{6} H_{14} + 19 O_{2} \to 12 C O_{2} + 14 H_{2} O$

The coefficient of O₂ is 19, meaning 19 moles of O₂ are required.

Q34: What is pH of a 1 molar solution of an acid that has a Ka - 10.8?

10

8

4

None of these

Explanation

For a strong acid with a high $K_a$ value (10.8), it fully ionizes in water.

pH is calculated as $pH = -log[H^+]$ , and for a 1 M strong acid, $[H^+] = 10^{-4}$ , so pH = 4.

Q35: Which of the following atoms has the largest diameter?

مندرجہ ذیل میں سے کون سے جوہری کا سب سے بڑا قطر ہے؟

I

Br

Cl

None of these

Q36: The major reason that phenol is a better Bronsted acid than cyclohexanol is _____?

فینول سائکلوہیکسنول سے بہتر برونسٹڈ ایسڈ ہے جس کی بڑی وجہ _____ ہے؟

It is a better proton donor

The phenyl group is an electron withdrawing group by induction, which stabilizes the action formed in the reaction

Phenol is able to stabilize the anion formed in the reaction by resonance

None of these

Q37: Why is oxygen-hydrogen absorption of CH3OH such a broad band in the infrared?

Hydrogen bonding broadens the absorption

Resonance broaden the absorption

Hyperconjugation resonance broadens

Rotational energy

Q38: Find the error: Most slugs and snails breathe using a lung which opens through a small hole in the side of its bodies.

Of its bodies

Which opens

Breathe

None of these

Q39: Order of reaction is defined as _______?

رد عمل کی ترتیب _______ کے طور پر بیان کی گئی ہے؟

Number of reactants

Power of concentration terms in the rate law equation

Rate of reactions

None of these

Q40: Water containing calcium and phosphate is called _____?

کیلشیم اور فاسفیٹ پر مشتمل پانی کو _____ کہا جاتا ہے؟

Permanent hard water

Permanent soft water

Temporary hard water

None of these