White is NOT a property of metals?
ductile
malleable
conduct heat and electricity
have many oxidation states
high melting points anti boiling points
Correct answer is D
No explanation has been provided for this answer.
I and II only
I, II and III only
II and III only
II, II and IV only
III and IV only
Correct answer is A
No explanation has been provided for this answer.
The high boiling point of hydrogen fluoride can be explained in terms of
covalent bonds.
dative bonds.
dipole-dipole bonds.
electrovalent (ionic) bonds
hydrogen bonds.
Correct answer is E
No explanation has been provided for this answer.
The oxidation number of X in \(XO_{4}^{3-}\) is
1
-2
3
4
5
Correct answer is E
The oxidation number of O is 2-
Therefore, let the oxidation number of X be a
a + (-2 x 4) = -3
a - 8 = -3
a = -3+8
a = 5
How much sodium hydroxide is required to make 250 cm3 of 0.1 molar solution? Na=23; 0=16; H=1]
10.0 g
4.0g
2.0 g
1.0g
0.1 g
Correct answer is D
no of moles of Na = molar concentration X volume
= 0.1 x \(\frac{250}{1000}\) = 0.025
no of moles = \(\frac{m}{M}\)
mass = no of mles x molar mass = 0.025 x 40 = 1.0g ( molar mass of NaOH = 40g/mol)