Freeze drying<span> (or lyophilization) removes water from the ice cream by lowering the </span>air pressure<span> to a point where ice sublimates from a </span>solid<span> to a </span>gas<span>. The ice cream is placed in a </span>vacuum chamber<span> and frozen until the water </span>crystallizes<span>. The air pressure is lowered, creating a partial vacuum, forcing air out of the chamber; next heat is applied, </span>sublimating<span> the ice; finally a freezing coil traps the vaporized water. This process continues for hours, resulting in a freeze-dried ice cream slice. </span>
Answer: a supposition or proposed explanation made on the basis of limited evidence as a starting point for further investigation.
Explanation: definition
Answer:
Explanation:
Translated:
Calculate the amount of sugar (C12 H22 O11) in the morning tea if a teaspoon contains 5g of sugar?
Given parameters
Mass of sugar = 5g
Unknown:
Amount of the sugar =?
Solution:
A mole is the amount of substance that contains avogadro's number of particles i.e 6.02 x 10²³
Therefore, to find the number of moles contained in the teaspoon of sugar we use the expression below:
Number of moles = 
Molar mass of C₁₂H₂₂O₁₁ = (12x12) + (1x22) + (16x11) = 342g/mol
Number of moles = 
= 0.015mol of sugar
or 0.015 x 6.02 x 10²³, 8.8x10²¹atoms of sugar
If the two gases has a total pressure of 5.7 atm and one of the gases has a partial pressure of 4.1 the the other one has the pressure of 1.6
Δ H reaction = q / n where q: amount of heat released and n is number of moles of substance.
q = m . C . ΔT where:
m = mass of substance (g)
C = Specific heat capacity (4.18)
ΔT = change in temperature = 24.25 - 23.16 = 1.09
q = 1000 x 4.18 x 1.09 = 4556 J = 4.556 kJ
number of moles (n) = Molarity (M) x Volume (L)
= 0.185 M x 0.07 L = 0.01295 mole
Δ H = q / n = - (4.556 kJ / 0.01295 mole) = -351.8 kJ / mol
Note: it is exothermic reaction (-ve sign) i.e. temperature is raised
