Answer:
The mass of 2,50 moles of NaCl is 146, 25 g.
Explanation:
First we calculate the mass of 1 mol of NaCl, starting from the atomic weights of Na and Cl obtained from the periodic table. Then we calculate the mass of 2.50 moles of compound, making a simple rule of three:
Weight NaCl= Weight Na + Weight Cl= 23 g+ 35,5 g= 58, 5 g/ mol
1 mol ------ 58, 5 g
2,5 mol---x= (2,5 mol x 58, 5 g)/ 1 mol = <u>146, 25 g</u>
The answer would be 0.55 moles! good luck!
There are 4 significant figures! Start counting after the first non-zero digit :)
Hope this helps.
Answer:
5.625 grams
Explanation:
Start your equation with what you have been given. Place the units you need in your answer on the right side of the equal sign.
225mg
----------- X ----------- X ------------- = ? g
lb
Now start to fill in your equation and use a conversions to get rid of the units you don't want. Convert mg into grams first. The child's weight (25 lb) is placed over 1 just to get the equation lined up properly so you can see how the units cancel out.
225 mg 1 g 25 lb 5.625 g
--------------- X --------------- X ------------- = ---------------
lb 1000 mg 1 1
The lb on the top and bottom cancel each other out and you are left with just grams. Even though it is over one, that is the same at just 5.625 grams.
B. kinetic energy is the best answer
