Answer:
C. To determine how efficient reactions are.
D. To determine how much reactant they need.
Explanation:
When you are doing a reaction, you are hoping for a percent yield to close of 100%. You make the reaction and determine how many product you obtain. If you know the percent yield of a reaction you can calculate the amount of reactant you need to obtain a determined amount of product.
Having this in mind:
A. To balance the reaction equation. false. To calculate percent yield you need to balance the reaction before. You don't use percent yield to balance the reaction
B. To determine how much product they will need. false. You determine how much product you obtain after the reaction. How much product you need is independent of percent yield
C. To determine how efficient reactions are. true. A way to determine efficience of a reaction is with percent yield. An efficient reaction has a high percent yield.
D. To determine how much reactant they need. true. If you know percent yield of a reaction you can know how many reactant you must add to obtain the amount of product you want.
Ur cars exhaust tank ur freezer ur toaster ur microwave ur shower
<span>LiOH+HBr---> LiBr +h20. Moles of LiOH = 10/24 = 0.41moles. According to stoichiometry, moles of LiOH = moles of LiBr = 0.41moles. Therefore mass of LiBr =moles of LiBr x molecular weight of LiBr = o.41 x 87 = 35.67g. Hope it helps </span>
VSEPR notation gives a general formula for classifying chemical species based on the number of electron pairs around a central atom. However, not all species have the same molecules.
For example, carbon dioxide and surfer dioxide are both species, but one is linear and another one is bent.
x=3
Use the pythagorean theorem:
a^2 + b^2 = c^2
4^2 + x^2 = 5^2
16 + x^2 = 25
x^2 = 25-16
x^2 = 9
√x^2 = √9
x = 3
