Reaction group 2

The metals of Group 2 react readily with oxygen to form compounds of general formula MO. When each of these oxides is added to water, which forms the most alkaline ?

• MgO

• CaO

• SrO

• BaO

Calcium oxide is added to water and the resulting mixture is filtered

This filtrate is X

When carbon dioxide is bubbled through filtrate X, a white precipitate is formed.

Which equation for this reaction of filtrate X with carbon dioxide is correct?

• CaO + CO₂ -> CaCO₃

• Ca(OH)₂ + CO₂ -> CaO + H₂CO₃

• 2CaO + H₂O + CO₂ -> CaCO₃ + Ca(OH)₂

• Ca(OH)₂ + CO₂ -> CaCO₃ + H₂0

River water in a chalky agricultural area may contain Ca²⁺, Mg²⁺ , CO^2-₃, HCO^-_3, Cl^- , and NO^-₃ ions. In a waterworks, such water is treated by adding a calculated quantity of calcium hydroxide.

What will the precipitated following the addition of calcium hydroxide?

• CaCl₂

• CaCO₃

• Ca(NO₃)₂

• Mg(NO₃)₂

Steam is passed over heated magnesium to give compound X and hydrogen.

what is not the property of Compound X ?

• It has a high melting point

• It is a basic oxide

• It is a white solid

• It is very soluble in water

A metal, X, reacts with water to produce a colourless solution which gives a white precipitate when mixed with aqueous sulphuric acid.

what is metal X ?

• Barium

• Magnesium

• Potassium

• Sodium

Which statement about the oxides and hydroxides of the Group 2 elements Mg, Ca, Sr and Ba is correct ?

• Each of the oxides reacts readily with water to form pH 12 or above

• Magnesium oxide is used as a furnace lining because it has giant molecular structure and hence a high melting point

• The hydroxides are produced directly by the thermal decomposition of the corresponding nitrates

• The solubility of hydroxides increases from Mg to Ba

X is an s-block element. X form an insoluble carbonate with the formula XCO3. X forms a hydroxide that is more soluble than strontium hydroxide.

what could be the identity of X ?

• Barium

• Calcium

• Cobalt

• Rubidium

What can be seen when a piece of magnesium ribbon is placed in cold water?

• A vigorous effervescence occurs

• Bubbles of gas form slowly on the magnesium

• The magnesium floats on the surface of the water and reacts quickly

• The magnesium glows and a white solid is produced

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

When calcium is burnt in oxygen, what colour is the flame?

• Green

• Red

• White

• Yellow

What is the starting line of ‘lagu Amanah Rakyat’ ?

• Mara perkasa menjunjung amanah rakyat

• Hari ini hari mulanya hari esok berjaya

• Demi satu keunggulan bangsa yang berdaulat

• Entah apa yang merasukimu