Answer:
0.2mol/dm³
Explanation:
Given parameters:
Mass of Na₂CO₃ = 10.6g
Volume of solution = 500mL
Unknown:
Molarity of solution = ?
Solution:
The molarity of a solution can be determined using the expression below:
Molarity =
Number of moles =
Molar mass of Na₂CO₃ = 2(23) + 12 + 3(16) = 106g/mol
Number of moles = = 0.1mol
Convert mL to dm³;
500mL will give 500 x 10⁻³dm³or 0.5dm³
So;
Molarity = = 0.2mol/dm³
Look at the periodic table to find the charge on atoms.
Magnesium is +2 and Nitrogen is -3. Since there are two nitrogen charge 2*-3 = -6 there needs to be 3 Mg then (3*2+ = 6+) to pair with the two nitrogen.
3 Mg(+2) + 2 N(-3) = Mg3N2
Double the friction of the object
Answer:
28.45L
Explanation:
1mole of a gas occupy 22.4L at stp. This implies that 1mole of He also occupy 22.4L at stp.
Now if 1mole of He occupied 22.4L at stp, then, 1.27mol will occupy = 1.27x22.4 = 28.45L
Answer:
0.0428 M
Explanation:
Because we're asked to calculate the molarity of nickel(II) cation, we need to <u>determine all sources for that species</u>, in this case, all Ni⁺² comes from the nickel(II) bromide solid (NiBr₂).
We use the molecular weight of NiBr₂ to calculate the moles of Ni:
1.87 g NiBr₂ ÷ 218.49g/mol * (1molNi⁺²/1molNiBr₂) = 8.55x10⁻³ mol Ni⁺²
Then we <u>divide the moles by the volume in order to calculate the concentration</u>:
8.55x10⁻³ mol Ni⁺² / 0.200 L = 0.0428 M