OpenStudy (superhelp101):

Question:

2 years ago
OpenStudy (superhelp101):

I have 3 questions that I just wanted to make sure on.

2 years ago
OpenStudy (superhelp101):

How many milliliters of a 1.25 molar hydrochloric acid (HCl) solution would be needed to react completely with 60.0 grams of calcium metal? Ca (s) + 2HCl (aq) yields CaCl2 (aq) + H2 (g) (1 point) 1200 ml I picked this one 2400 ml 3750 ml 9600 ml A student dissolves 4.5 g of sodium chloride (NaCl) into 75 g of water (H2O). Which of the following statements is correct regarding the resulting solution when it is compared to the pure solvent? (1 point) Both the vapor pressure and the boiling point will increase. The boiling temperature and the freezing temperature will decrease. The freezing temperature will increase and the vapor pressure will decrease. The vapor pressure will decrease and the boiling temperature will increase. This one? When dissolved in 1000 g of water, which chemical compound will produce a solution with the greatest freezing point depression? (1 point) 5.0 g of sodium chloride (NaCl) 9.2 g of potassium chloride (KCl) 11 g of calcium fluoride (CaF2) This one? 20 g of glucose (C6H12O6) I'm not 100% sure on what i picked :/

2 years ago
OpenStudy (superhelp101):

@sweetburger

2 years ago
OpenStudy (sweetburger):

so 60g of Ca is like 1.5moles so were probably going to need about 3 moles of HCl due to the 1:2 ratio so saying that we need 3 moles of HCl we can say that 3molesHCl/1.25m/L = 2.4L or 2400ml

2 years ago
OpenStudy (superhelp101):

oh oops I made a silly error on that one

2 years ago
OpenStudy (melodious):

hey

2 years ago
OpenStudy (melodious):

teehee

2 years ago
OpenStudy (superhelp101):

:)

2 years ago
OpenStudy (sweetburger):

For the next question adding salt would increase the boiling point above 100C temperature lower the vapor pressure and lower the freezing point temperature below 0C.

2 years ago
OpenStudy (melodious):

@superhelp101 is it me?

2 years ago
OpenStudy (superhelp101):

so the last option is correct

2 years ago
OpenStudy (sweetburger):

Yes i believe so @superhelp101

2 years ago
OpenStudy (superhelp101):

great! @sweetburger

2 years ago
OpenStudy (vera_ewing):

Nice work, @sweetburger ! :)

2 years ago
OpenStudy (melodious):

vera_ you got 99 points?

2 years ago
OpenStudy (sweetburger):

For the last question you would have to find the amount in moles of each substance and then recognize the van hofft factor which would become like a coefficient increasing the freezing point depression

2 years ago
OpenStudy (melodious):

give me a medal pls

2 years ago
OpenStudy (sweetburger):

so we have .08moles of NaCl so .08x2 we have .12moles of KCl so .12x2 we have .14moles of CaF2 so 3x.14 and we have .11moles of C6H12O6 so .11x1. We dont even have to multiply them out and we know that .14x3moles of CaF2 will be the largest value. Any of the values found above would be multiplied times a constant of a specific solvent and would give a temperature change.

2 years ago
OpenStudy (sweetburger):

So ya your choice was correct.

2 years ago
OpenStudy (superhelp101):

yayaya :) thanks bunches!

2 years ago