To find the Percent Composition of an atom, you use this formula:
Mass of element in the compound you're studying on ( in this case it's 5 since there is 5 Hydrogens) over the mass of the compound (which is here 79), Multiplied by 100 since you want a percent.
So we get:
So you get about:
So, the percent composition of Hydrogen in NH4HCO3 is 6.3%
Hope this Helps! :D
<span>
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:
Explanation:
find the attached solution below
Answer:
6.The moles of water can be gotten by dividing the mass of water in step 5 by the molecular mass of water(18.01528 g/mol).
7 The moles of the dried copper salt can be calculated by dividing he mass of dried salt in step 4 by the molecular mass of CuCl2 (134.4620 g/mol).
Look below for further explanation
Explanation:
Assumption:The lab experiment involved heating copper (II) chloride dihydrate in a crucible to remove the water.(hydrate)
1. weigh and record the mass of an empty crucible (tare wt).
2.Add the copper hydrate salt, and reweigh (total wt). The mass of the added hydrate salt can be derived by subtracting the tare wt from the total weight wt (= net wt of the hydrate).
3.The next is to heat the crucible at some temperature above 100 C until the mass of the crucible plus dried salt is known to be constant (cool the crucible in a dessicator).
4.The mass of the dried salt is obtained by subtracting the tare wt from the mass of the crucible plus dried salt. (mass of dried salt)
5.The mass of water is calculated by subtracting the mass of the dried salt from the mass of the hydrate salt.(in step 2)
6.The moles of water can be gotten by dividing the mass of water in step 5 by the molecular mass of water(18.01528 g/mol).
7 The moles of the dried copper salt can be calculated by dividing he mass of dried salt in step 4 by the molecular mass of CuCl2 (134.4620 g/mol).
Answer:
is a solution whose pH is above 7or is a basic solution