Answer:
He took a deep breath and splashed some water on his face.
Explanation:
I took the test on Edmentum.
Answer:
Explanation:
Cubic decimeter is the same unit as liter; so, mole per cubic decimeter is mole per liter, and that is the unit of concentration of molarity. Thus, what is asked is the molarity of the solution. This is how you find it.
1. <u>Take a basis</u>: 1 dm³ = 1 liter = 1,000 ml
2. <u>Calculate the mass of 1 lite</u>r (1,000 ml) of solution:
- density = mass / volume ⇒ mass = density × volume
Here, the density is given through the specific gravity
Scpecific gravity = density of acid / density of water
Take density of water as 1.00 g/ml.
- density of solution = 1.25 g/ml
- mass solution = 1.25 g/ml × 1,000 ml = 1,250 g
3. <u>Calculate the mass of solute</u> (pure acid)
- % m/m = (mass of solute / mass of solution) × 100
- 56 = mass of solute / 1,250 g × 100
- mass of solute = 56 × 1,250g / 100 = 700 g
4. <u>Calculate the number of moles of solute</u>:
- moles = mass in grams / molar mass = 700 g / 70 g/mol = 10 mol
5. <u>Calculate molarity (mol / dm³)</u>
- M = number of moles of solute / liter of solution = 10 mol / 1 liter = 10 mol/liter.
Balanced chemical equation:
* moles of oxygen
4 Al + 3 O2 = 2 Al2O3
4 moles Al -------------- 3 moles O2
9.30 moles Al ---------- moles O2
moles O2 = 9.30 * 3 / 4
moles O2 = 27.9 / 4 => 6.975 moles of O2
Therefore:
Molar mass O2 = 31.9988 g/mol
n = m / mm
6.975 = m / 31.9988
m = 6.975 * 31.9988
m = 223.19 of O2
A chromosome is a tightly coiled X of genetic material that has genes on it.
Hope this helps!
