Practice Pakistan's most useful MCQs for competitive exams

A substance is analyzed and found to have an emperical formula of CH2 and a molar mass of 56g/mole. What is the molecular formula of the compound?

• (A)  C2H4
• (B)  C3H6
• (C)  C4H8
• (D)  C5H10

Answer

Submitted By :Ali Uppal

A compound is determined to have an emperical formula of C2H6O and a molar mass of 138 g/mole. What is the molecular formula?

• (A)  C2H6O
• (B)  C6H18O3
• (C)  C6H12O6
• (D)  C2H5O

Answer

Submitted By :Ali Uppal

A sample of an iron and oxygen ore has a mass of 35.8 grams. The iron in the compound has a mass of 27.9 grams. What is the percent iron in the ore?

• (A)  74% Fe
• (B)  75% Fe
• (C)  77% Fe
• (D)  78% Fe

Answer

Submitted By :Ali Uppal

What is the mass percent of silver in silver notrate, AgNO3?

• (A)  64.5%
• (B)  65.6%
• (C)  63.5%
• (D)  61.5%

Answer

Submitted By :Ali Uppal

How many moles are in 22.2 grams of Calcium chloride, CaCl2?

• (A)  0.2 moles
• (B)  0.3 moles
• (C)  0.4 moles
• (D)  0.5 moles

Answer

Submitted By :Ali Uppal

Tetraethyl lead is used as______?

• (A)   Pain Killer
• (B)   Fire Extinguisher
• (C)   Mosquito Repellent
• (D)   Petrol Additive

Answer

Submitted By :Ali Uppal

Electric bulb filament is made of__________?

• (A)  Copper
• (B)   Aluminum
• (C)   Lead
• (D)   Tungsten

Answer

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Oxidation state +1 for phosphorous is found in___________?

• (A)  H3PO3
• (B)  H3PO4
• (C)  H3PO2
• (D)  H2P2O7

Answer

Submitted By :Ali Uppal

SO2 reacts with Cl in sunlight to form__________?

• (A)  Sulphur dioxide
• (B)  Sulphuryl chloride
• (C)  Suphanyl chloride
• (D)  All of the above

Answer

Submitted By :Ali Uppal

Argon gas was discovered by_______?

• (A)  Rayleigh
• (B)  Ramsay
• (C)  Lockerey
• (D)  Dalton

Answer

Submitted By :Ali Uppal