MCQ Collection
Pakistan MCQs
Practice Pakistan questions with answers and explanations.
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Correct Answer: D. The actual number of each type of atom in one molecule
Explanation:
A molecular formula is a whole-number multiple of the empirical formula.
It applies to substances composed of discrete molecules.
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Correct Answer: A. Uptake of material by formation of membrane vesicles
Explanation:
The plasma membrane surrounds material and pinches inward.
Phagocytosis and pinocytosis are forms of endocytosis.
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Correct Answer: A. An equation with equal numbers of each atom on both sides
Explanation:
Balancing follows conservation of atoms and mass.
Coefficients change amounts, not chemical formulas.
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Correct Answer: B. The study of matter, its properties, composition, and changes
Explanation:
Chemistry examines what matter is made of and how it behaves.
It also studies energy changes accompanying chemical processes.
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Correct Answer: B. Relative numbers of particles or moles
Explanation:
Equation coefficients give stoichiometric ratios.
They may be interpreted as molecule or mole ratios.
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Correct Answer: C. Anything that has mass and occupies space
Explanation:
Matter includes solids, liquids, gases, and plasma.
It is composed of atoms, molecules, or ions.
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Correct Answer: C. The reactant consumed first and limiting product formation
Explanation:
Once the limiting reactant is used up, no more product can form.
Other reactants may remain in excess.
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Correct Answer: D. A pure substance made of one type of atom
Explanation:
An element cannot be broken down chemically into simpler substances.
Each element is identified by its atomic number.
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Correct Answer: D. A reactant remaining after the limiting reactant is consumed
Explanation:
An excess reactant is supplied beyond the stoichiometric requirement.
Some remains when the reaction is complete.
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Correct Answer: A. A pure substance containing elements chemically combined in fixed proportions
Explanation:
Compounds have definite formulas and characteristic properties.
Their components can be separated only by chemical means.
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Correct Answer: A. Maximum product predicted from stoichiometry
Explanation:
Theoretical yield assumes complete reaction and no losses.
It is calculated from the limiting reactant.
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Correct Answer: B. A physical combination of substances with variable composition
Explanation:
Mixture components retain much of their individual identity.
They can often be separated by physical methods.