# What is the gram formula mass of caso4.2h2o?

What is the gram formula mass of caso4.2h2o?

So your practically trying to finding the molar mass of CaSO₄.2H₂O and that is found by adding all the molar masses of the individual elements:

So Ca = 40 g/mol
S  = 32 g/mol
O = 16 /mol
H = 1 g/mol

molar mass of CaSO₄.2H₂O = [(40) + (32) + (16 × 4) + (2 × 1 × 2) + (2 × 16)]
= 172 g/mol

Answer : The gram formula mass of is, 172 g/mole

Explanation :

As we know that,

Molar mass of calcium (Ca) = 40 g/mole

Molar mass of sulfur (S) = 32 g/mole

Molar mass of oxygen (O) = 16 g/mole

Molar mass of hydrogen (H) = 1 g/mole

Now we have to calculate the gram formula mass of In , there are 1 calcium atom, 1 sulfur atom, 6 oxygen atom and 4 hydrogen atom.

The gram formula mass of = Therefore, the gram formula mass of is, 172 g/mole

a. The gram formula mass of CaSO4.2H2O equals 172 grams/mole

b. The percentage by mass of H2O in CaSO4.2H2O is 20.9%

c. The molecular formula for naphthalene is C10H8

d. The total number of moles in 80.0grams of C2H5Cl is 1.24 moles

e. 4.76moles of Na3PO4 contains 780.64 grams of Na3PO4

Explanation:

RMM = Relative Molecular Mass

a. To calculate the gram formula mass of CaSO4.2H2O, you would have to add the atomic mass of the individual elements that make up to compound. Here are the atomic masses of individual elements present in gypsum; Ca=40, S=32, O=16, H=1.

CaSO4.2H2O = 40+32+(16x4)+2((1x2)+16) = 172 grams/mole

b. % by mass of H2O in gypsum = (RMM of 2H2O/RMM of gypsum) x 100

RMM of 2H2O = 2((1x2)+16)=36 gram/mole

RMM of CaSO4.2H2O (gypsum) = 172 grams/mole

% by mass of H2O in gypsum = (36/172) x 100 = 20.9% of H2O

c. The empirical formula of a compound only shows the simplest ratio of atoms in a particular compound not the actual number of atoms. The actual number of atoms in a compound is shown in its molecular formula, which can be used to calculate the RMM of the compound. A specific number (n) multiplied by the number of atoms in an empirical formula gives the molecular formula. (C=12, H=1)

(Empirical formula)n = Molecular formula

(Total sum of atomic masses of elements in empirical formula)n = Total sum of atomic masses of elements in molecular formula

RMM of naphthalene = 128 grams/mole

((12x5)+(1x4))n = 64n

64n = 128

n = 128/64 = 2

Therefore, (C5H4)2 = C(5x2)H(4x2) = C10H8

d. Number of moles of C2H5Cl = mass of C2H5Cl/RMM of C2H5Cl

Say number of moles of C2H5Cl = y

Mass of C2H5Cl = 80.0 grams

RMM or gram-formula mass of C2H5Cl = 64.5 grams/mole

y = 80.0/64.5 = 1.24 moles

e. Number of moles of Na3PO4 = mass of Na3PO4/RMM of Na3PO4

Number of moles of Na3PO4 = 4.76 moles

gram-formula mass of Na3PO4 = 164 grams/mole

mass of Na3PO4 = x

4.76 = x/164

x = 4.76 x 164 = 780.64 grams

Explanation:

Data

CaSO₄ 2H₂O

Gram formula mass = ?

Process

1.- Determine the number of elements in the compound

Calcium        1

Sulfur            1

Hydrogen          4

Oxygen              6

2.- Multiply the number of atoms by their atomic weight

Calcium        1  x 40 = 40

Sulfur            1 x 32 = 32

Hydrogen          4 x 1 = 4

Oxygen              6 x 16 = 96