Answer:
63.05% of MgCO3.3H2O by mass
Explanation:
<em>of MgCO3.3H2O in the mixture?</em>
The difference in masses after heating the mixture = Mass of water. With the mass of water we can find its moles and the moles and mass of MgCO3.3H2O to find the mass percent as follows:
<em>Mass water:</em>
3.883g - 2.927g = 0.956g water
<em>Moles water -18.01g/mol-</em>
0.956g water * (1mol/18.01g) = 0.05308 moles H2O.
<em>Moles MgCO3.3H2O:</em>
0.05308 moles H2O * (1mol MgCO3.3H2O / 3mol H2O) =
0.01769 moles MgCO3.3H2O
<em>Mass MgCO3.3H2O -Molar mass: 138.3597g/mol-</em>
0.01769 moles MgCO3.3H2O * (138.3597g/mol) = 2.448g MgCO3.3H2O
<em>Mass percent:</em>
2.448g MgCO3.3H2O / 3.883g Mixture * 100 =
<h3>63.05% of MgCO3.3H2O by mass</h3>
Answer:
For example, friction between our shoes and the floor stop us from slipping and friction between tyres and the road stop cars from skidding. Friction is sometimes unhelpful. For example, if you don't lubricate your bike regularly with oil, the friction in the chain and axles increases.
Explanation:
Answer:
8.33mol/L
Explanation:
First, let us calculate the molar mass of of formaldehyde (CH2O). This is illustrated below:
Molar Mass of CH2O = 12 + (2x1) + 16 = 12 + 2 + 16 = 30g/mol
Mass of CH2O from the question = 0.25g
Number of mole CH2O =?
Number of mole = Mass /Molar Mass
Number of mole of CH2O = 0.25/30 = 8.33x10^-3mole
Now we can calculate the molarity of formaldehyde (CH2O) as follow:
Number of mole of CH2O = 8.33x10^-3mole
Volume = 1mL
Converting 1mL to L, we have:
1000mL = 1L
Therefore 1mL = 1/1000 = 1x10^-3L
Molarity =?
Molarity = mole /Volume
Molarity = 8.33x10^-3mole/1x10^-3L
Molarity = 8.33mol/L
Therefore, the molarity of formaldehyde (CH2O) is 8.33mol/L
A change in the Earth's magnetic<span> field resulting in the </span>magnetic<span> north being aligned with the geographic south, and the </span>magnetic<span> south being aligned with the geographic north. Also called </span>geomagnetic reversal<span>.</span>