Molecular Mass

This is just easy. MOLARITY OF THIS COMPOUND IS 3MOLDM-3.

The concentration is 2 mol/L.

This reaction is:
2 Al + 2 H2O + 2 NaOH = 2 NaAlO2 + 3 H2
From 4 moles of Al 6 moles of hydrogen are obtained.

The molar mass is the sum of atomic weights of the conained elements in the formula.

This depends on the specific recipe of a producer.

The answer is 2,09 moles.

750 L hydrogen gas at 0 0C and 1 at is equal to 33,44 moles.

48,5 g sample of CS2 is the equivalent of 0,637 moles.

Obtain the molecular mass by determining the m/z value of the molecular ion peak (rightmost in the spectrum).

Only one mole of copper.

number of moles = mass of the element/molar mass of the element

This molecular formula is C9H12.

The answer is 3,375 moles oxygen.

0.125 moles HCl/1 liter = 0.125 M HCl
HCl dissociates completely, so [H+] = 0.125 M
pH = -log [H+] = -log 0.125
pH = 0.903

8,75 moles of oxygen are needed.

4,35 moles of silver is equal to 469 g (0,469 kg).

In a container the volume remain constant but the pressure increase.

978 g calcium contain 24,4 moles.

By atoms it is 50% sodium and 50% chlorine.

By mass (sodium is 23.0, chlorine is 35.5, salt is 58.5) is 39.3% sodium and 60.7% chlorine.

The answer is 7,18.10e-10 moles.

20,32 g of lithium nitride can be obtained.

Two moles is 12,044 280.10e23 molecules, atoms or ions.

Divide all elements by the smallest number of moles (0.04) to get
1Na, 1S and 1.5 O. Next, multiply all by 2 as to obtain all whole numbers, and you arrive at
2Na, 2S and 3 O. So empirical formula will be Na2S2O3.

The mass of 1.23 moles of iron is 58,69 g.

It is only a convention; it is more simple to work with a decimal system as in SI.
The old English system of units is obsolete, nonrational and riduculous today.