Chemistry Korir

The respiration process during which glucose undergoes slow combustion by combining with oxygen in the cells of our body to produce energy, is a kind of:

• Exothermic process

• Endothermic process

• Reversible process

• Physical process

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

A chemical reaction does not involve:

• Formation of new substances having entirely different properties than that of the reactants

• Breaking of old chemical bonds and formation of new chemical bonds

• Rearrangement of the atoms of reactants to form new products

• Changing of the atoms of on element into those of another element to form new products

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-2

NGSS.MS-PS1-5

One of the following processes does not involve a chemical reaction. That is:

• Melting of candle wax when heated

• Burning of candle wax when heated

• Digestion of food in our stomach

• Ripening of banana

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

It is necessary to balance a chemical equation in order to satisfy the law of:

• Conservation of motion

• Conservation of momentum

• Conservation of energy

• Conservation of mass

Tags

NGSS.MS-PS1-5

When ferrous sulphate is heated strongly it undergoes decomposition to form ferric oxide as a main product accompanied by a change in colour from:

• Blue to green.

• Green to blue.

• Green to brown.

• Green to yellow.

The displacement reaction between iron (III) oxide and a metal X is used for welding the rail tracks. Here X is:

• Copper granules

• Magnesium ribbon

• Sodium pellets

• Aluminium dust

The neutralization reaction between an acid and a base is a type of:

• Double displacement reaction

• Displacement reaction

• Addition reaction

• Decomposition reaction

Before burning in air, the magnesium ribbon is cleaned by rubbing with a sand paper to:

• Make the ribbon surface shinier

• Remove the layer of magnesium oxide from the ribbon surface

• Remove the layer of magnesium carbonate from the ribbon surface

• Remove the moisture from the ribbon surface

What happens when copper rod is dipped in iron sulphate solution :-

• Copper displaces iron

• Blue color of copper sulphate solution is obtained

• No reaction takes place

• Reaction is exothermic

Tags

NGSS.MS-PS1-2

What is the another name of quick lime?

• Calcium hydroxide

• Calcium oxide

• Carbon dioxide

• Sodium oxide