Chemistry Class 10 Quiz

A type of chemical reaction where one substance replaces another in a compound.

The concentration of hydronium ions (H3O+) in a solution determines its acidity. The higher the concentration of H3O+ ions, the more acidic the solution.

A process where water is absorbed by roots and transported upwards through the stem to the leaves using a specialized network of vascular tissues called xylem.

The process of photosynthesis occurs in the leaves of plants, where chlorophyll captures sunlight's energy to convert carbon dioxide and water into glucose (sugar) and oxygen. This glucose provides energy for the plant's growth and development.

Hypermetropia, also known as farsightedness, is a refractive error where the eye focuses light behind the retina, making distant objects appear clear, but near objects blurry.

Myopia, also known as nearsightedness, is a refractive error where the eye focuses light in front of the retina, making near objects appear clear, but distant objects blurry.

The resistance (R) of a wire is directly proportional to its length (l) and inversely proportional to its cross-sectional area (A). This relationship can be expressed mathematically as R = (ρl)/A, where ρ is the resistivity of the material.

Resistivity (ρ) is the inherent property of a material that quantifies its resistance to the flow of electric current. It is defined as the resistance (R) of a wire made of that material with a unit length (l) and unit cross-sectional area (A).

A chemical reaction where a more reactive element displaces a less reactive element from its compound. In this case, hydrogen (H) is more reactive than the metal 'X', so it displaces 'X' from its compound, resulting in the formation of hydrogen gas (H2).

Alveoli are tiny air sacs in the lungs responsible for gas exchange, while nephrons are functional units of the kidney responsible for filtering blood and producing urine. Alveoli are located in the lungs, while nephrons are located in the kidneys.

The process of photosynthesis in plants involves the use of sunlight, water, and carbon dioxide to produce glucose (a sugar) and oxygen as a byproduct. Some desert plants have adapted to conserve water by possessing special features like thick cuticles, sunken stomata, or reduced leaf size.

A convex mirror always forms a virtual, upright, and diminished image. This is because parallel rays of light reflect from a convex mirror as if they are coming from a point behind the mirror, which is the focal point.

A convex lens is the type of lens shown. The image formed is real, inverted, and magnified. The object is placed between the focal point (F) and the center of curvature (C) of the lens which results in a magnified real image.

A concave lens always forms a virtual, upright, and diminished image. This is because parallel rays of light passing through a concave lens diverge as if they originated from a point behind the lens, which is the focal point.

Concave lenses are used in corrective lenses for people with myopia (nearsightedness) and in magnifying glasses.

Producers like plants are essential for any ecosystem, as they form the base of the food chain. Removing producers would disrupt the entire ecosystem as consumers would lose their food source. While lions are consumers, their removal wouldn't directly impact the entire food chain, but rather their prey populations.

The strength of the magnetic field produced by a current-carrying wire decreases with distance from the wire. As the compass moves away from the wire, the magnetic field acting on it weakens, causing a smaller deflection.

Increasing the current flowing through the wire will increase the magnetic field strength around it, leading to a larger deflection of the compass needle.

The direction of the magnetic field around a straight current-carrying wire can be determined using the right-hand rule. Point your thumb in the direction of the current, and your curled fingers will indicate the direction of the magnetic field lines.

Substitution reactions primarily involve the replacement of an atom or group of atoms in a molecule. Saturated hydrocarbons, containing only single bonds, are less reactive towards substitution reactions compared to unsaturated hydrocarbons, which have double or triple bonds.

Methane and propane are both alkanes, and their isomers display similar chemical properties. Their combustion reactions release energy, making them valuable fuels. The straight-chain alkanes and their branched isomers exhibit similar properties but differ in their boiling points and physical characteristics.

Ethyne burns with a very hot flame due to the presence of carbon-carbon triple bonds, making it suitable for welding. However, ethyne mixed with air (containing oxygen) is not suitable because it forms an explosive mixture, posing a safety hazard.

Sodium salts of long-chain carboxylic acids (soaps) form micelles in water, where the hydrophobic tails are inside and the hydrophilic heads are towards the water. They can trap grease and dirt, making them effective cleansing agents. Sodium salts of long chain sulfonic acids (detergents) work similarly.

The preparation of soap involves reacting an ester (e.g., methyl acetate, CH3COOCH3) with a strong base (like sodium hydroxide, NaOH) in a process called saponification. This reaction breaks the ester bond, producing a carboxylate salt (soap) and an alcohol.

The presence of XY chromosomes in a fetus indicates a male sex.

Prenatal sex determination can be misused for practices like female feticide, which involves selectively aborting female fetuses based on gender preference.

The potential difference across a resistor is the voltage drop across it, calculated using Ohm's law: V = IR, where V is the potential difference, I is the current, and R is the resistance.

The resistance of a resistor is determined by its ability to impede the flow of electric current. It can be calculated using Ohm's law: R = V/I, where R is the resistance, V is the voltage, and I is the current.

The power consumed by a lamp is the rate at which it converts electrical energy into light and heat. It is calculated using the formula: P = VI, where P is the power, V is the voltage, and I is the current.

Two resistors are connected in series when they are connected one after the other, forming a single path for current flow. In this case, the total resistance is the sum of individual resistances: Rtotal = R1 + R2.

Two resistors are connected in parallel when they are connected across the same two points, providing multiple paths for current flow. In this case, the reciprocal of the total resistance is equal to the sum of the reciprocals of individual resistances: 1/Rtotal = 1/R1 + 1/R2.

Joule's law of heating states that the heat generated by an electric current flowing through a resistor is directly proportional to the square of the current, the resistance, and the time for which the current flows. Mathematically: H = I²Rt, where H is the heat, I is the current, R is the resistance, and t is the time.

A type of asexual reproduction in plants where new plants develop from specialized buds called suckers, growing from the base of the parent plant.

1. Faster Propagation: Suckers develop quickly into new plants, allowing for efficient large-scale planting.
2. Genetic Uniformity: All offspring are genetically identical to the parent, ensuring desirable traits are preserved.

Male flowers typically produce pollen, which is necessary for pollination. In the case of the banana plant, even though it produces only male flowers, it can still be involved in pollination through cross-pollination.

While the banana plant reproduces through suckers, a process of asexual reproduction, the offspring aren't completely identical to the parent due to mutations that can occur during cell division. This leads to subtle variations in the offspring.

The placenta is a vital organ that connects the developing fetus to the mother's uterus.

The placenta has villi, which are finger-like projections that increase the surface area for exchange of nutrients and oxygen from the mother to the fetus, and waste products from the fetus to the mother.

A smaller placenta with fewer villi will limit the exchange of nutrients and oxygen to the developing fetus, which can negatively impact the baby's growth and development.

The uterus is the region in the female body where the embryo develops. It's adapted for nourishing the baby with a thick lining called the endometrium, which is richly supplied with blood vessels to provide nutrients and oxygen.

Ethene (C₂H₄) is the first member of the alkene homologous series. When ethene reacts with concentrated sulfuric acid, it undergoes an addition reaction to form ethyl hydrogen sulfate (C₂H₅HSO₄).

Combustion reactions are a specific type of oxidation reaction involving rapid reaction with oxygen, producing heat and light. While all combustion reactions involve oxidation, not all oxidation reactions involve a rapid reaction with oxygen to produce heat and light. For example, rusting is a slow oxidation process without significant heat or light.

The bending of shoots towards sunlight is a growth response called phototropism. The plant hormone auxin is responsible for this response. Auxin accumulates on the shaded side of the shoot, causing cells on that side to elongate more than those on the illuminated side, resulting in bending.

The folding of leaves in the 'touch-me-not' plant is due to a rapid change in turgor pressure in specialized cells called motor cells. When touched, these cells lose water quickly, causing the leaves to fold and droop. This response is called thigmotropism, a response to touch.

The growth of the pollen tube towards the ovule is also a type of tropism called chemotropism. The pollen tube is attracted by chemicals called chemotropic substances released by the ovule. This is similar to phototropism, where the plant shoot is attracted to sunlight.

The folding of leaves in the 'touch-me-not' plant is a rapid, reversible movement, similar to the movements of animal body parts. Both involve changes in turgor pressure or muscle contractions. However, in plants, the movements are usually slower and less complex.