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1. Remember (sum of products) - (sum of reactants)
So ΔHrxn = 2 ΔHf [H2(g)] + ΔHf [Ca(OH)2(s)] - 2 ΔHf [H2O(l)] - ΔHf [Ca(s)]
= 2*0 + -986.09 kJ/mol - 2*(-285.8 kJ/mol) - 0
Do the math and you'll have the answer. BTW the ΔHf [H2(g)] and ΔHf
[Ca(s)] were 0 because these are elements in their standard states.
</span>HOPE THIS HELPS ;)
Answer:
See below.
Explanation:
The period is not the same regardless of the string length.
The longer the length the greater is the period ( the period varies directly with the square root of the length).
The equation of the relationship is T = 2π√(l/g) where l = the length of the string and g is the acceleration due to gravity.
The electron gain for iron means that it is reduced (answer C)
Explanation
Redox reaction is made up of two halves.
That is a reduction half and a oxidization half.
In the reduction half electrons are gained which result to decrease in oxidation number.
In the Oxidization half electrons are lost which result to increase in oxidation number.
iron is therefore reduced since it gains electrons
Mole to Mole.
Assuming you're referring to converting in general, there must always be a mole to mole conversion.
Gram to gram would be incorrect as you must have a molar conversion in order to do so.
Gram to mole would be incorrect because that would leave out molecular conversions which would require three steps rather than two.
Mole to molecule is incorrect as it leaves out grams, depending on the circumstances and equation provided.
Thus, through process of elimination, mole to mole is the correct answer.
Hope this helps!