You'll need Avogadro's number for this. NH3 has 1 Nitrogen and 2 Hydrogen. You'll multiply the molar mass of each times Avogadro's number. So:
molar mass N x 6.022x10^23 x 1 Nitrogen= total A
Molar mass H x 6.022x10^23 x 2 Hydrogen= total B
Add total A+B = your answer
I don't have a calculator or periodic table but if you plug in the numbers you'll get your answer. Hope it helps.
Answer:
“A” since liquid has to above 32F
Well first you need to know what a mixure is. A mixture must be made of two or more elements or compounds. There are several ways to seperate a mixture, that is, to isolate each substance (element or compound). You can do this with melting point (i.e. a block of aluminum and iron that have been melted, mixed and then cooled. To seperate the Al from the Fe, you can start to melt it. The Al melts at a much lower temp than the Fe, and therefore will liquify before Fe.)
948 or 9.48 x 10^2
There are two sets of rules for significant figures
• One set for addition and subtraction
• Another set for multiplication and division
You used the set for multiplication and division.
This problem involves addition and subtraction, and the rule is
The number of places after the decimal point in the answer must be <em>no greater than the number of decimal places in every term</em> in the sum.
Thus, we have
78.9
+890.43
-21.
= 948.33
The "21" term has the fewest digits after the decimal point (none), so the answer must have no digits after the decimal point.
To the correct answer is 948 = 9.48 x 10^2. It has three significant figures.
