Answer:
Step-by-step explanation:
. Calculate the number of moles in positive and negative ions in 2,25 moles of calcium fluoride (CaF).
We are told that there are 2.25 moles of CaF. But calcium is divalent and fluorine is monovalent. The correct molecular formula is CaF2.
Assuming it dissolved completely, there will be 2.25 moles of Ca^+2. But the will be 2*(2.25 moles) = 4.50 moles of fluorine negative ions, F^-1
2. What is the mass in grams of 2.94 moles of lead(II) nitrate (Pb(NO))? Show your work.
Lead nitrate is Pb(NO3)2, not Pb(NO). The molar mass of lead nitrate is 331.2 grams/mole. So 2.94 moles of the substance will contain:
(2.94 moles Pb(NO3)2)*( 331.2 grams/mole) = 974 grams to 3 sig figs
3. Calculate the number of moles in 245g aluminum nitrite (A1(NO2)3). Show your work.
The molar mass of aluminum nitrite is 165 grams/mole.
(245g)/(165 grams/mole) = 1.48 moles [grams cancel and moles moves to the top]