<span>50.2 kJ = 333 kJ/kg * mass of water
mass of water is 0.15075075075075075075075075075075 kg
therefore mass of unfrozen water is 0.10924924924924924924924924924925 kg</span>
Answer:
molecular mass Al(OH)₃ = 78 amu
Explanation:
Molar mass = ∑ atomic masses
Al(OH)₃ => Al + 3O + 3H = 1(27amu) + 3(16amu) + 3(1amu) = (27 + 48 + 3)amu = 78amu*
*atomic mass units
Answer:
The second sample will produce 1563 grams of fluorine (F2)
Explanation:
The reaction will be MgF2 → Mg + F2
The stoichiometry ratio of MgF2 and F2 is 1 : 1.
That means for 1 mole of MgF2 consumed there is 1 mole of F2 produced.
The first sample produces 2.15 kg of magnesium and 3.36 kg of fluorine
The second sample produced 1 kg of magnesium and x kg of fluorine
This we can show in the following equation =
2.15kg / 3.36 kg = 1kg / x
2.15/3.36 = 0.63988
0.63988 = 1/ x
x= 1/0.63988 = 1.563 kg
1.563kg = 1563 grams
The second sample will produce 1563 grams of fluorine (F2)
1) Chemical equation
<span>2NH4Cl(s)+Ba(OH)2⋅8H2O(s)→2NH3(aq)+BaCl2(aq)+10H2O(l)
2) Stoichiometric ratios
2 mol NH4Cl(s) : 54.8 KJ
3) Convert 24.7 g of NH4Cl into number of moles, using the molar mass
molar mass of NH4Cl = 14 g/mol + 4*1 g/mol + 35.5 g/mol = 53.5 g/mol
number of moles = mass in grams / molar mass
number of moles = 24.7 g / 53.5 g/mol = 0.462 moles
4) Use proportions:
2 moles NH4Cl / 54.8 kJ = 0.462 moles / x
=> x = 0.462 moles * 54.8 kJ / 2 moles = 12.7 kJ
Answer: 12.7 kJ</span>
