General Science GK Questions with Answers – Page 104

Three grams of hydrogen, 48 grams of oxygen and 42 grams of nitrogen each come to 1.5 moles, while two grams of carbon is only about 0.17 mole, so carbon holds a different number of particles.

A colloid only looks uniform to the eye; it is in fact a heterogeneous mixture, so this is the statement that is not true.

Copper sulphate holds five water molecules, sodium carbonate ten and gypsum two, so the order asked for is 5, 10 and 2.

The statement in the question is Avogadro's law, given by the Italian scientist Amedeo Avogadro in 1811.

A simple pendulum about one metre long completes one full swing in roughly two seconds, and a pendulum of this length is called the seconds pendulum.

A reading of 113 on the Fahrenheit scale works out to 45 degrees Celsius, and adding 273 to that gives about 318 K. Fahrenheit is turned into Celsius with the relation C = (F - 32) x 5/9, so (113 - 32) x 5/9 = 81 x 5/9 = 45…

Mass by mass percentage of a solution is the mass of the solute divided by the mass of the whole solution, multiplied by 100.

In the given equation sodium hydroxide, which is a base, reacts with sulphuric acid to give sodium sulphate and water, and a reaction in which an acid and a base cancel each other to form a salt and water is called neutralisation.

The heat produced by a current is given by Joule's law of heating, H equals I squared into R into t. Here the current is 0.3 A, the resistance is 418 ohms and the time is 1 minute, which is 60 seconds.

A quantity that has both magnitude and direction is a vector, and momentum, which is the product of mass and velocity, is a vector because velocity has a direction.

Ammonium chloride is the salt of a strong acid, hydrochloric acid, and a weak base, ammonium hydroxide, so its aqueous solution is acidic and its pH is less than 7.

Stomata are the tiny pores on the surface of a leaf through which a plant takes in carbon dioxide and gives out oxygen and water vapour, so the exchange of gases takes place through them.

Adding water to an acid spreads the same number of hydrogen ions through a larger volume, so the number of hydrogen ions per unit volume falls, and that process is called dilution.

The object stands between the pole and the focus of the concave mirror, so the image formed is virtual, erect and enlarged, and the magnification is positive.

Birds and mammals are warm-blooded, which means they keep their body temperature nearly constant whatever the temperature outside, and a pigeon is a bird.

The weight of an object is the force with which the earth attracts it, so the force of gravity acting on an object is its weight.

In the equation given, glucose reacts with oxygen to release carbon dioxide, water and energy, and the breakdown of food inside the cell to release energy is called respiration.

Deposition is the direct change of a substance from the gaseous state to the solid state, without passing through the liquid state in between.

The lateral meristem, better known as the cambium, lies as a ring along the length of the stem and root and divides to add new xylem on its inner side and new phloem on its outer side, so the stem grows thicker year after year; this is secondary growth, and…

Blood is classed as a connective tissue because its cells lie in a matrix, and because that matrix, the plasma, is liquid it is called a fluid connective tissue; the red cells, white cells and platelets float in it and it connects the organs of the body by carrying gases…