Chemical Reaction | MCQs

Explanation

Henry Cavendish - He discovered hydrogen gas and the composition of water contains two parts of hydrogen and one part of oxygen.

Symbol: H

Atomic mass: 1.00784 u

Atomic number: 1

Named by: Antoine Lavoisier (1783)

Explanation

A decomposition reaction involves a single compound breaking down into simpler substances.

AB → A + B is the correct format for decomposition.

Explanation

Explanation

ٹیسٹ کی تیاری کے لیے بار بار پیپرز میں آنے والے سپیلنگ ضرور یاد کریں

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Explanation

• An acid is a substance that donates a proton (H+ ion) in a reaction, increasing the concentration of hydrogen ions in an aqueous solution.
• Examples of acids include hydrochloric acid (HCl), sulfuric acid (H2SO4), and acetic acid (CH3COOH).

Explanation

• If the pH value is greater than 7, the solution is basic (also known as alkaline).
• This means that the concentration of hydroxide ions (OH-) is higher than the concentration of hydrogen ions (H+).

Key Points:

• pH < 7: Acidic
• pH = 7: Neutral
• pH > 7: Basic (or alkaline)

Explanation

The equilibrium constant, Kc, for the reaction:

N2 + O2 ⇌ 2NO is unitless (No unit).

Since the number of moles of gas is the same on both the reactant and product sides (2 moles).

The concentration terms in the equilibrium constant expression cancel out, leaving Kc without units.

Explanation

Explanation

The flame test is a qualitative analysis technique used to identify certain elements based on the color they produce when heated in a flame.

In the case of copper halides (such as copper chloride or copper bromide), the flame test produces a bluish-green color, which indicates the presence of copper.

Explanation

Qc (reaction quotient) is defined as the ratio of the molar concentrations of products to reactants, each raised to the power of their respective stoichiometric coefficients (coefficients in the balanced chemical equation).