Question

How many Ca2+ ions are in a sample of CaSO4 having a total mass of 68.07 g?
(Given: The molar mass of CaSO4 is 136. 14 g/mol; Avogadro's number is 6.022 x
1023 /mol)
O 6.022 x 1023 Ca2+
ions
3.011 x 1023 Ca2+ ions
3.011 x 1022 Ca2+ ions
4.516 x 1023 Ca2+ ions
O 1.024 x 1024
Ca2+
ions

Answer 1

Answer:

There are  

17.01

Explanation:

The chemical formula for calcium phosphate is  

Ca

3

(PO

4

)

2

. This means that in one mole of calcium phosphate, there are three calcium ions and two phosphate ions.

Answer 2

The number of Ca²⁺ ions in the CaSO₄ sample is 3.011  * 10²³ Ca²⁺ ions

Determination of number of moles

• The formula for number of moles is given as:
• number of moles = mass/molar mass

Number of moles of CaSO₄ present in 68.07 g of CaSO₄ is first determined:

Molar mass of CaSO₄ = 136 g/mol

mass of CaSO₄ = 68.07

Number of moles = mass / molar mass

number of moles = 68.07 /136

Number of moles = 0.5 moles

Equation for the dissociation of CaSO₄:

CaSO₄ ------> Ca²⁺ + SO²⁻

I mole of CaSO₄ produces 1 mole Ca²⁺ ions

0.5 moles of CaSO₄  produces 0.5 moles of Ca²⁺ ions

Number of Ca²⁺ ions = number of moles of Ca²⁺ ions * Avogadro number

Number of Ca²⁺ ions = 0.5 * 6.022 * 10²³

Number of Ca²⁺ ions = 3.011  * 10²³ Ca²⁺ ions

Therefore, the number of Ca²⁺ ions in the CaSO₄ sample is 3.011  * 10²³ Ca²⁺ ions

Learn more about moles and ions at: https://brainly.com/question/23902691