Chem B

In which of the following compounds does hydrogen form ionic compounds?

• CH4

• HCl

• NH3

• NaH

Tags

NGSS.HS-PS1-3

An organic compound has the empirical formula CH2. If its molar mass is 42gmol−1, what is its molecular formula?  (C = 12.0, H = 1.0)

• C2H4

• C3H4

• C3H6

• C4H8

Pure water can be made to boil at a temperature lower than 100°C by

• reducing its quantity

• decreasing the external pressure

• distilling it

• increasing the external pressure

The valence electrons of ₁₂Mg are in the

• 3s orbital

• 2px orbital

• 2s orbital

• 1s orbital

Tags

NGSS.HS-PS1-1

NGSS.HS-PS1-2

The number of Hydrogen ions in 1.0dm³ of 0.02moldm⁻³ tetraoxosulphate(VI) acid is   [NA=6.02 × 10²³]

• 1.2 × 10²³

• 2.4 × 10²³

• 1.2 × 10²²

• 2.4 × 10²²

Tags

NGSS.HS-PS1-5

The most suitable substance for putting out petrol fire is

• water

• carbon(IV) oxide

• fire blanket

• sand

The following factors would contribute to environmental pollution except

• production of ammonia

• manufacture of cement

• photosynthesis

• combustion

Tags

NGSS.HS-LS2-7

Which of the following CANNOT be an empirical formula?

• CH

• CH2

• P2O5

• N2O4

One of the criteria for confirming the purity of benzene is to determine its

• heat capacity

• boiling point

• mass

• colour

How many atoms are contained in 0.2 mole of nitrogen? [NA = 6.02 × 10²³]

• 1.20 × 10²³

• 2.41 × 10²³

• 3.62 × 10²³

• 4.84 × 10²³