Answer:
31.78 grams
25.55%
Explanation:
The balanced reaction for ammonium chloride with calcium oxide will be:
2NH4Cl + Ca(OH)2 ---> CaCl2 + 2NH3 + 2H2O
The molecular weight for ammonium chloride(NH4Cl ) is 53.49g/mol, while the molecular weight for ammonium(NH3) is 17g/mol. The number of theoretical yield of ammonia from 100g of ammonium chloride will be:
100g / (53.49g/mol) * 2/2 * 17g/mol= 31.78 grams
If the actual yield is 8.12g, the percent yield will be: 8.12g/31.78g * 100% =25.55%
Hey there!
Exothermic reactions release heat, causing its temperature to fall. If the reaction is lessening the temperature of the object while releasing all the heat, then you know that the reaction is indeed exothermic. Hope this helps!
Answer:
There are 3600 pages to 2 significant figures
Explanation:
Working only with the information given, we have that there are 23 books each with about 31 chapters.
This means that if 1 book has 31 chapter, the 23 science books will have
31 X 23 chapters =713 chapters in total.
If each chapter contains 5 pages, for the 713 chapters we will have a total of 713 X 5 pages = 3565 pages.
Rounding off the answer to 2 significant figures , we are looking to have only two non-zero figures in our answer. To do this, we count two numbers from the left. This will be numbers 3 and 5.
Next, we check the net number after 5 to see if it is greater than 5 if it is, we will have to add the number (1 ) to the 5. This shows that we are approximating upwards, to account for the fact that that number has passed the middle point.
After this, we change the remaining two numbers (6 and 5) to zeroes.
This will give us 3600 pages.
Answer:
Explanation:
(NH4)3 PO4 +NaOH arrow Na3PO4 +3NH3 +3H2O
Start by seeing what happens with the Na. You need 3 on the left, so put a 3 in front of NaOH
(NH4)3 PO4 +3NaOH arrow Na3PO4 +3NH3 +3H2O Next work with the nitrogens. YOu have 3 on the left and 3 on the right, so they are OK. Next Go to the stray oxygens.
You have 3 on left in (NaOH) and three on the right in 3H2O so they are fine as well. The last thing you should look at are hydrogens.
There are 12 + 3 on the left which is 15. There are 9 (in 3NH3) and 6 more in the water. They seem fine.
Why didn't I do something with the PO4^(-3)? The reason is a deliberately stayed away from them and balanced everything else. Since they were untouched with 1 on the left and 1 on the right, they are balanced.
Species Na H O N PO4
Left 3 15 3 3 1
Right 3 15 3 3 1
