## Test 1 number 7

Karolina herrera1F
Posts: 33
Joined: Sat Feb 02, 2019 12:15 am

### Test 1 number 7

Can someone please explain what equation they used for test 1 number seven and why? if you have to convert?

Jeril Joseph 1B
Posts: 55
Joined: Mon Jun 17, 2019 7:23 am
Been upvoted: 1 time

### Re: Test 1 number 7

So, I first converted the 225 mg. of cisplatin to grams and used the molar mass to convert the grams to moles of cisplatin. I then used the molarity= moles of solute/volume in liters equation to get the volume in liters I needed; plugging in the given molarity and the calculate moles of solute.

Yilun Ding
Posts: 31
Joined: Tue Jun 25, 2019 12:15 am

### Re: Test 1 number 7

Using the mass to calculate the moles of cisplatin first, then use the moles to divide the molarity ti get the volume. Next time you can figure out the relations by units.

Posts: 36
Joined: Mon Jun 17, 2019 7:23 am

### Re: Test 1 number 7

Since they gave you mass in mg and they have you and molarity, you know to use the equation M=(moles)/Liters. Usually, you would use M1V1=M2V2 when they give you three values or when the question specifically has the word dilute in it. So, you would take the mg and make it into grams them use the molar mass to get it into moles. Using this information, you would solve for liters, 1.8x10^-4 = (0.000850)/L = 4.72 L

simmoneokamoto3K
Posts: 50
Joined: Mon Jun 17, 2019 7:22 am

### Re: Test 1 number 7

The equation was for molarity which is M (molarity) = (moles)/(liters). If you have different measurements like mg you need to convert, so for question seven you needed to plug in the values after converting mg to liters.