Answer:
All of the energy from the Sun that reaches the Earth arrives as solar radiation, part of a large collection of energy called the electromagnetic radiation spectrum. Solar radiation includes visible light, ultraviolet light, infrared, radio waves, X-rays, and gamma rays. Radiation is one way to transfer heat.
Answer:
The recovery of pure caffeine is 67.3% of the original, crude sample.
Explanation:
Step 1: Data given
Mass of pure caffeine = 1.69 grams
Original mass of sample = 2.51 grams
Step 2: What is the percent recovery of pure caffeine from crude?
Percentage = (mass of recovery / original mass) *100%
Percentage = (1.69 grams/2.51 grams) *100%
Percentage = 67.3 %
The recovery of pure caffeine is 67.3% of the original, crude sample.
Answer:
Because for dilute and aqueous solutions the mass of solvent will be a very close value to the volume of solution.
Explanation:
Molar concentration is defined as:
And molal concentration is defined as:
And:
Msolution=Msolute+Msolvent
For <em>dilute solutions</em>, we have small amounts of solute, then we have:
Msolution=Msolute+Msolvent, and as the mass of solute is very small: Msolution≅Msolvent
If the solution is <em>also aqueous</em> (water as solvent), and considering that the density of water is around 1 gm/cm3 or 1 kg/m3:
Msolvent≅Msolution≅Vsolution
Therefore, if we look to the molar and molal equations, we have the same numerator in both (moles of solute) and nearby numbers for the denominator, giving to the molar and molal concentration close values.