Answer:
0.0199moles
Explanation:
The number of miles of a substance can be calculated using the formula:
Number of moles (n) = Mass (M) / Molar mass (MM)
In this question, the mass of Magnesium element (Mg) = 0.478 g while the atomic mass is 24
Therefore, number of moles of Magnesium is:
Moles = 0.478/24
Moles = 0.01992
Hence, 0.0199 moles of Magnesium are contained in 0.478 g of the element.
Answer:
Calcium chlorate | Ca(ClO3)2 - PubChem.
Explanation:
From the ideal gas law, PV = nRT, we can rearrange the equation to solve for T given the other parameters.
T = PV/nR
where P = 0.878 atm, V = 1.20 L, n = 0.0470 moles, and R = 0.082057 L•atm/mol•K. Plugging in our values, we obtain the temperature in Kelvin:
T = (0.878 atm)(1.20 L)/(0.0470 mol)(0.082057 L•atm/mol•K)
T = 273 K
So, the second answer choice would be correct.
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.
Answer:
isn't this like solid liquid and gas