Midterm Chemistry Quiz for Class 7

A substance with a sour taste containing acidic compounds.

Acids produced from naturally occurring sources like fruits and vegetables.

Acids derived from minerals found in the Earth.

Acids that are weaker and safer to consume.

Acids that are very dangerous to consume, even in diluted form.

The process of adding a small amount of acid to a large amount of water.

Substances that conduct electricity when dissolved in water.

A substance like sodium hydrogencarbonate that neutralizes excess acid in the stomach.

A substance that turns red litmus paper blue and has a pH greater than 7.

A substance that changes colour in the presence of an acid or base.

A natural or synthetic substance used to determine the acidity or alkalinity of a solution.

A scale that measures the acidity or alkalinity of a substance.

The reaction between an acid and a base, resulting in the formation of a salt and water.

A compound formed when an acid reacts with a base.

A substance that is neither acidic nor basic, having a pH of 7.

A salt formed when a strong acid reacts with a weak base. For example, ammonium chloride (NH4Cl) is formed by the reaction of hydrochloric acid (HCl) with ammonia (NH3).

A salt formed when a weak acid reacts with a strong base. For example, sodium acetate (CH3COONa) is formed by the reaction of acetic acid (CH3COOH) with sodium hydroxide (NaOH).

A salt formed when a strong acid reacts with a strong base. For example, sodium chloride (NaCl) is formed by the reaction of hydrochloric acid (HCl) with sodium hydroxide (NaOH).

A change in the physical properties of a substance, such as its shape, size, color, or state of matter. These changes are usually reversible.

A change that results in the formation of a new substance with different chemical properties. These changes are typically irreversible.

Iron reacts with oxygen and water vapor in the air to form iron oxide, commonly known as rust.

A process that prevents rust formation by coating iron with a protective layer, usually zinc.

The reaction of iron with copper sulphate results in the displacement of copper by iron and the formation of iron sulphate, causing a green solution and a reddish copper coating on the iron nail.

A chemical reaction that releases energy in the form of light, heat, or sound.

A chemical reaction that requires energy input, usually in the form of heat or light.

The process of converting a substance from a solid to a liquid state by adding heat.

The amount of water that is stored underground in the spaces between rocks and soil.

The upper level of groundwater, where the ground is saturated with water.

The process of rainwater seeping into the ground, replenishing the groundwater.

A layer of rock or soil that can hold and transmit groundwater.

Using a system of tubes and pipes to deliver water directly to plant roots, minimizing water waste.

Collecting and storing rainwater for later use, helping to replenish groundwater.

The continuous movement of water on, above, and below the surface of the Earth.

The process of water changing from a liquid to a gas, driven by heat.

A process where organic matter is broken down by bacteria in the absence of oxygen. It produces biogas, which can be used as fuel or to generate electricity.

The removal of floating debris and grease from wastewater. Often involves a skimming device.

A system of pipes that collect and transport wastewater from homes and buildings to a wastewater treatment plant.

Microorganisms that thrive in oxygen-rich environments and play a crucial role in breaking down organic matter in wastewater treatment.

A type of wastewater treatment where air is injected into the water to support the growth of aerobic bacteria, which decompose organic matter.

The solid waste material that settles to the bottom of a wastewater treatment tank during the activated sludge process.

The process of separating grit, sand, and pebbles from wastewater by slowing down the flow of wastewater.

The process of removing large objects, such as plastic bags, from wastewater using screens or grates.