~ A mole is a unit of 6*10^23.
~One mole of carbon atoms has a mass of exactly 12 g.
~ Because magnesium atoms each have twice the mass of carbon atoms ( 24Mg compared with 12C), one mole of magnesium has a mass of 24 g.
~ Rather, one mole of any element has a mass in grams that is equal to its relative atomic mass.
Answer:
1. MgCl2 + Zn -> Mg + ZnCl2
2. 2Al + 6H2O(g) -> 2Al(OH)3 + 3H2
3. 2Cd + O2 -> 2CdO
4. I2 + KF -> it's not going to react
5. Zn + H2SO4 -> ZnSO4 + H2
6.2KBr + Cl2 -> 2KCl + Br2
7. AgNO3 + Na -> NaNO3 + Ag
8. 2NaCl + F2 -> 2NaF + Cl2
9. AgNO3 + Mg(NO3)2 + Ag
10. Ni + H2SO4 -> NiSO4 + H2
11. Al + K2SO4
12. FeCl3 + 3Mn-> 3MnCl + Fe
13. 2Na + 2H2O -> 2NaOH + H2
14. 2K + MgBr2 -> 2KBr + Mg
15. Zn + Pb(NO3)2 -> Pb + Zn(NO3)2
16. 2AlBr3+ 3Cl2 -> 2AlCl3 + 3Br2
Answer: Option (a) is the correct answer.
Explanation:
A weak acid is defined as an acid that dissociates partially when dissolve in water or a polar solvent.
For example, acetic acid is a weak acid and when dissolved in water it dissociates partly into ions as follows.

And, a strong acid is defined as an acid which when dissolved in water dissociates completely into ions.
For example, HCl is a strong acid and when dissolved in water it dissociates completely.

Thus, we can conclude that the statement a weak acid solution consists of mostly non-ionized acid molecules, is true.
Answer:
A. 336 L
Explanation:
STP is 0 °C and 1 bar.
At STP, the molar volume of a gas is 22.71 L.
Volume = 15 mol × 22.71 L/mol
Volume = 341 L
===============
The above answer is not in your list of options.
It appears that you are using the <em>OLD</em> (pre-1982) definition of STP, at which the molar volume of a gas is 22.4 L.
Then
V = 15 mol × 22.4 L/mol = 336 L