35) How much calcium is contained in 35.0 g of calcium fluoride? 35) A) 15.0 g B

Question

35) How much calcium is contained in 35.0 g of calcium fluoride? 35) A) 15.0 g B) 7.70g C) 18.0g D) 1.990 36) Read the water level with the correct number of significant figures. 36) A) 5.32 mL B) 5.3 mL C) 5.3200 mL D) 5.320 mL E) 5 mL 37) Two or more substances in variable proportions, where the composition is constant throughout are 37) A) a compound B) a heterogeneous mixture. C) an element D) a crystalline solid. E) a homogeneous mixture. 38) Determine the number of protons, neutrons, and electrons in the following: 38) 40 18 A) p+ 18 n 18 22 B)p+ = 18 n°=22 e-=40 C)p+ = 18 n°-22 e. = 18 E) p+,40 n°-22 e. # 18 39) lons differ in the number of 39) A) neutrons and protons. B) neutrons. C) protons. D) electrons and protons E) electrons.

Explanation / Answer

35)
Molar mass of CaF2,
MM = 1*MM(Ca) + 2*MM(F)
= 1*40.08 + 2*19.0
= 78.08 g/mol


mass(CaF2)= 35.0 g

number of mol of CaF2,
n = mass of CaF2/molar mass of CaF2
=(35.0 g)/(78.08 g/mol)
= 0.4483 mol
This is number of moles of CaF2

one mole of CaF2 contains 1 moles of Ca
So, number of moles of Ca = 1 * number of moles of CaF2
= 1 * 0.4483
= 0.4483

Molar mass of Ca = 40.08 g/mol

mass of Ca,
m = number of mol * molar mass
= 0.4483 mol * 40.08 g/mol
= 18.0 g

Answer: C

I am allowed to answer only 1 question at a time

Related Questions

Navigate

• Browse (All)
• Browse 3
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.