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.
Noble gas molecules are held together by
van der Waals forces
hydrogen bonds
dative bonds
covalent bonds
Correct answer is A
No explanation has been provided for this answer.
Which of the following elements is diatomic?
Sodium
Oxygen
Iron
Neon
Correct answer is B
The seven diatomic elements are Hydrogen, Nitrogen, Oxygen, Fluorine, Chlorine, Iodine, Bromine.