Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.
The gas law which describes the relationship between volume and temperature is
Boyle's law
Charles' law
Dalton's law
Graham's law
Correct answer is B
No explanation has been provided for this answer.
The percentage by mass of calcium in Ca(OCI)2 is [Ca = 40.0; CI = 35.5; O = 16.0]
28.0%
31.6%
43.8%
44.5%
Correct answer is A
Molar mass of \(Ca(OCl)_2\) = 40 + (16 + 35.5)x2 = 143
% by mass of calcium in the compound =\(\frac{mass of calcuim}{molar mass of compound}\) x 100%
% calcium = \(\frac{40}{143} \times100\)
= 27.98% = 28%
464.30 cm3
625.00 cm3
1000.00 cm3
2153.80 cm3
Correct answer is A
number of moles = molar concentration x volume(\(dm^3\))
molar concentration(C) = 0.25mol/dm3, volume = ? and number of mole(n) = \(\frac{mass}{molar mass}\) = \(\frac{6.5}{56}\) ( where 56g/mol = molar mass of KOH)
\(\frac{6.5}{56}\) = 0.25 x V
V = \(\frac{0.11607}{0.25}\) = 0.46428dm^3 → 464.3cm^3
4
3
2
1
Correct answer is C
C\(_2\)H\(_2\) + yH\(_2\) → C\(_2\)H\(_6\)
To balance the equation, we must have 2 carbon atoms on both sides and 6 hydrogen atoms.
On the LHS and RHS, carbon = 2 atoms.
On the LHS, Hydrogen = 2 + 2y.
On the RHS, Hydrogen = 6.
⇒ 2 + 2y = 6
2y = 4
y = 2.
Which of the following statements about nuclear reaction is correct? The reaction
involves neutrons only
takes place inside the nucleus
is governed by temperature and pressure
involves protons and electrons only
Correct answer is B
A nuclear reaction is semantically considered to be the process in which two nuclei, or a nucleus and an external subatomic particle, collide to produce one or more new nuclides.