Answer:
We need 10.14 grams of sodium bromide to make a 0.730 M solution
Explanation:
Step 1: Data given
Molarity of the sodium bromide (NaBr) = 0.730 M
Volume of the sodium bromide solution = 135 mL = 0.135 L
Molar mass sodium bromide (NaBr) = 102.89 g/mol
Step 2: Calculate moles NaBr
Moles NaBr = Molarity NaBr * volume NaBr
Moles NaBr = 0.730 M * 0.135 L
Moles NaBr = 0.09855 moles
Step 3: Calculate mass of NaBr
Mass NaBr = 0.09855 moles * 102.89 g/mol
Mass NaBr = 10.14 grams
We need 10.14 grams of sodium bromide to make a 0.730 M solution
Answer:
The answer is Hg.
Explanation:
Symbol for Mercury is Hg.
If you'd like the full working, here it is:
I calculated this by using the formula triangle.
Mass
Number Formula
Of moles Mass
To calculate the number if moles in a substance, you need to divide the Mass by the Formula mass. You get the formula mass by adding the atomic masses of the elements in the compound together. In this situation, H2O, it would be two hydrogen molecules plus one oxygen molecule which is 2 + 16. This is because the atomic mass of Hydrogen is 1 and the atomic mass of Oxygen is 16.
Now that we have the Formula mass we can go ahead and do the calculation since we already have the Mass. You do as follows:
Mass divided by Formula mass which is in this case - 25 divided by 18
By doing this calculation you will get the answer which is 1.38 moles which can be rounded to 1.4
Hope this helps :)
Answer:
A. stored energy
Explanation:
potential energy is stored energy.
kinetic energy is the energy of motion
Answer:
237.8L of water would need to be added.
Explanation:
The first thing to do is to identify that the equation to be used is M1V1=M2V2. (This equation works because it turns everything into moles which can then be compared).
Then figure out what information you have and what is being found. In this case:
M1 = 54.7 M
V1 = 1092 mL = 1.092 L
M2 = 0.25 M
V2 = unknown
Then solve the equation for whatever you are trying to find.
M1V1=M2V2
V2=M1V1/M2
Now you need to plug everything in.
V2=(54.7M*1.091L)/0.25M
V2=238.93L
That means that the solution needs a volume of 238.7L to gain a molarity of 0.25M but the starting solution already had a volume of 1.092 L meaning that to find the amount of solvent that needs to be added you just subtract the starting volume by the volume that the solution needs to be.
238.93L - 1.091L = 237.8L
Therefore the answer is that 237.8L needs to be added to a 1.092L 54.7M NaCl solution to make the concentration 0.25M.
I hope this helps. Let me know if anything is unclear.
