Answer:
A cold front forms when a cold air mass pushes into a warmer air mass. Cold fronts can produce dramatic changes in the weather. ... As the cold front passes, winds become gusty. There is a sudden drop in temperature, and also heavy rain, sometimes with hail, thunder, and lightning.
%Mass
Ar C = 12 g/mol, Mr C₄H₁₀ = 58 g/mol, Ar H = 1 g/mol
or
The reaction of baking soda or baking powder with the liquid in the batter: These ingredients react together and cause air bubbles to form. ... Heat of the oven: The heat of the oven can cause baking powder to react further and cause more air bubbles, and the heat also sets the structure of the cake.
Answer:
XY₂Z₄
2.35 mol Z
Explanation:
A sample of the compound contains 0.221 mol X, 0.442 mol Y, and 0.884 mol Z. We can find the simplest formula (empirical formula) by <em>dividing all the numbers of moles by the smallest one</em>.
X: 0.221/0.221 = 1
Y: 0.442/0.221 = 2
Z: 0.884/0.221 = 4
The simplest formula is XY₂Z₄.
The molar ratio of X to Z is 1:4. The moles of Z in a sample that contained 0.588 moles of X is:
0.588 mol X × (4 mol Z/1 mol X) = 2.35 mol Z
Ca(OH)2(aq) + 2HCl(aq)------> CaCl2(aq) + 2H2O(l) ΔH-?
CaO(s) + 2HCl(aq)-----> CaCl2(aq) + H2O(l), Δ<span>H = -186 kJ
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CaO(s) + H2O(l) -----> Ca(OH)2(s), Δ<span>H = -65.1 kJ
</span>
1) Ca(OH)2 should be reactant, so
CaO(s) + H2O(l) -----> Ca(OH)2(s)
we are going to take as
Ca(OH)2(s)---->CaO(s) + H2O(l), and ΔH = 65.1 kJ
2) Add 2 following equations
Ca(OH)2(s)---->CaO(s) + H2O(l), and ΔH = 65.1 kJ
<span><u>CaO(s) + 2HCl(aq)-----> CaCl2(aq) + H2O(l), and ΔH = -186 kJ</u>
</span>Ca(OH)2(s)+CaO(s) + 2HCl(aq)--->CaO(s) + H2O(l)+CaCl2(aq) + H2O(l)
Ca(OH)2(s)+ 2HCl(aq)---> H2O(l)+CaCl2(aq) + H2O(l)
By addig these 2 equation, we got the equation that we are needed,
so to find enthalpy of the reaction, we need to add enthalpies of reactions we added.
ΔH=65.1 - 186 ≈ -121 kJ
