Answer:
2%
Explanation:
.98 is 98% of one and therefore they are missing 2%
Speed
Explanation:
The distance travelled by a body per unit time
<span>The surface area is 109.3 square centimeters or 0.01093 square meters. The area formula requires that we use the radius of the disc. We can find the radius by diving the diameter by 2, so radius = 11.8/2 or 5.9 cm. We can use 3.14 as an approximation for π. The surface area is 3.14 * (5.9*5.9).
Since the diameter is given in cm, the surface area units are in square centimeters. To convert to meters, divide any measurement in centimeters by 100, but we need to convert to "square" meters, so we need to divide our square centimeters by 100 * 100, or by 10,000. Dividing 109.3 by 10,000 results in 0.01093 square "meters".</span>
If he was 30.8% too low, it means that he was at 69.2% of the boiling point needed. So 50o C is 69.2% of total.
In order to know what 100% is, you can divide the number by it's percentage and then multiply it by a hundred.
So: 50/30.8=1.623
1.623*100=162.3
So the correct boiling point of the liquid he was working with in the lab is 162.3 oC
Answer:
333.7 g.
Explanation:
- The depression in freezing point of water (ΔTf) due to adding a solute to it is given by: <em>ΔTf = Kf.m.</em>
Where, ΔTf is the depression in water freezing point (ΔTf = 20.0°C).
Kf is the molal freezing point depression constant of the solvent (Kf = 1.86 °C/m).
m is the molality of the solution.
<em>∴ m = ΔTf/Kf</em> = (20.0°C)/(1.86 °C/m) = <em>10.75 m.</em>
molaity (m) is the no. of moles of solute per kg of the solvent.
∵ m = (no. of moles of antifreeze C₂H₄(OH)₂)/(mass of water (kg))
∴ no. of moles of antifreeze C₂H₄(OH)₂ = (m)(mass of water (kg)) = (10.75 m)(0.5 kg) = 5.376 mol.
∵ no. of moles = mass/molar mass.
<em>∴ mass of antifreeze C₂H₄(OH)₂ = no. of moles x molar mass </em>= (5.376 mol)(62.07 g/mol) =<em> 333.7 g.</em>
