Chemical Reaction | MCQs

Explanation

• A non-metal atom forms an anion (a negatively charged ion) by gaining one or more electrons.
• This means that the atom acquires additional electrons to form a negative ion.

Explanation

• When one atom loses an electron to form a cation and another atom gains that electron to form an anion, the resulting attraction between the oppositely charged ions is an ionic bond.
• This type of bond is typically formed between a metal and a nonmetal, and is characterized by a transfer of electrons rather than a sharing of electrons (as in covalent bonds).

Explanation

• Magnesium (Mg) is an alkaline earth metal that loses two electrons from its outer shell to form a divalent cation (Mg²⁺).
• This means that it typically loses two electrons to form compounds, resulting in a valency of +2.

Explanation

• A hydrogen bond is a type of intermolecular force that arises between a highly electronegative atom (such as oxygen, nitrogen, or fluorine).
• A hydrogen atom that is bonded to a highly electronegative atom.
• This interaction is typically weak compared to covalent bonds.
• But it is strong enough to influence the physical and chemical properties of molecules.

Explanation

Thermochemistry is the study of chemical reactions and the energy changes that involve heat.

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RY24012023

Explanation

• Sugar (a solid) dissolves in water (a liquid) to form a solution, making it a classic example of a solid-liquid solution.
• The sugar molecules (solute) are dissolved in the water molecules (solvent), resulting in a homogeneous mixture.

Explanation

Water is made up of two elements, namely oxygen and hydrogen.

پانی دو عناصر سے بنتا ہے، یعنی آکسیجن اور ہائیڈروجن۔

Elements are pure chemical substances consisting of one type of atom.

Oxygen (O) and hydrogen (H) are both chemical elements that combine to form water (H₂O).

Explanation

Blood has a pH level of around 7.3, which is closest to neutral (pH 7).

Explanation

The pH scale ranges from 1 to 14, with:

• 1-6 being acidic
• 7 being neutral (neither acidic nor basic)
• 8-14 being basic (alkaline)

Explanation

• Litmus paper is a simple and effective way to test whether a substance is an acid or a base.
• It turns red in acidic solutions and blue in basic solutions.