The colour of K₂Cr₂O₇ in acidic medium is

• red

• green

• yellow

• pink

Formula of washing soda is

• Na₂CO₃.10H₂O

• Na₂CO₃

• Na₂SO₄.10H₂O

• None of the above

Which one of the following is an s-block element?

• Aluminium

• Chromium

• Niobium

• Potassium

The alkali metal that reacts with nitrogen directly to form nitride is

• Li

• Na

• K

• Rb

A white solid 'A' on heating gives off a gas which turns lime water milky. The residue is yellow when hot but turns white on cooling. This solid 'A' is

• zinc sulphate

• zinc carbonate

• lead sulphate

• lead carbonate

The molecular formula of bleaching powder is

• CaCl₂

• Ca₂OCl₂

• CaOCl₂

• CaCl₂.CaOCl

A solution of sodium metal in liquid ammonia is a strong reducing agent due to the presence of

• sodium atoms

• sodium hydride

• sodium amide

• solvated electron

Which of the following metals has highest melting point

• Barium

• Calcium

• Strontium

• Radium

99.

Which of the following pairs of compounds cannot exist together?

• NaHCO₃ and NaCl

• NaHCO₃ and NaOH

• NaHCO₃ and Na₂CO₃

• Na₂CO₃ and NaOH

Which of the following properties of lithium does not show diagonal relationship with magnesium?

• Formation of Li⁺ ion

• Formation of Li₃N

• Solubility of LiHCO₃

• Thermal decomposition of Li₂CO₃