An element is a pure substance which means it cannot be broken down by any means.
Answer:
Explanation:
Vaporization Equation => Q = m·ΔHv
m = 0.5Kg water = 500g water
ΔHv = Heat of vaporization = 540 calories/gram
∴Q = 500g x 540cal/g = 270,000 calories x 4.184 joules/cal = 1,129,680 joules = 1130 Kilojoules (3 sig. figs.)
Keep in mind that when two moles of potassium chlorate are decomposed, 3 moles of oxygen are produced.Think of the coefficients: since the mole ratio is 2 to 3, it means that<span> 2 mol KClO3 will turn into 3 mol O2.
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2kclO3->2kcl+3O2
In a chemical laboratory, a mortar and pestle function is to decrease surface area of a solute. The correct answer is B.
The mole fraction of solute in a 3.87 m aqueous solution is 0.0697
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calculation</h3>
molality = moles of the solute/Kg of the solvent
3.87 m dissolve in 1 Kg of water= 1000g
find the moles of water= mass/molar mass
that is 1000 g/ 18 g/mol= 55.56 moles
mole of solute = 3.87 moles
mole fraction is = moles of solute/moles of solvent
that is 3.87/ 55.56 = 0.0697
