Question

Calculate the mass, in kg, of each sample. a. 7.55 * 1026 cadmium atoms b. 8.15 * 1027 nickel atoms c. 1.22 * 1027 manganese atoms d. 5.48 * 1029 lithium atoms

Answer 1

141kg of Cadmium

794kg of Nickel

111kg of Manganese

6.32×10³kg of lithium

Step-by-step explanation:

From the question I guess the number of atomes for cadmium, nickel. Manganese and lithium are 7.55×10²⁶, 8.16×10²⁷, 1.22×10²⁷, 5.48×10²⁹ atoms respectively

1 mole of a substance contains 6.022×10²³ atoms

There are 1× 7.55×10²⁶/6.022×10²³ moles in 7.55×10²⁶ atoms of Cadmium

This is equal to 1.254×10³ moles

Also, the atomic mass of cadmium is 112.411 g/ mole i.e for 112.411 g you will have a molr of cadmium. For 1.254×10³moles, you will have 112.411×1.254×10³ grams= 140.96 ×10³ grams

1000g =1kg

153.50×10³ g = 140.96×10³/1000 kg or 141kg of Cadmium

b.

There are 1× 8.15×10²⁷/6.022×10²³ moles in 8.15×10²⁷ atoms of Nickel

This is equal to 1.353×10⁴ moles

Also, the atomic mass of nickel is 58.69 g/ mole i.e for 58.69 g you will have a mole of nickel. For 1.353×10⁴moles, you will have 58.69×1.353×10⁴ grams= 79.41 ×10⁴ grams

1000g =1kg

79.41×10⁴ g = 79.41×10⁴/1000 kg or 794kg of Nickel

c.

There are 1× 1.22×10²⁷/6.022×10²³ moles in 1.22×10²⁷atoms of Manganese

This is equal to 2.026×10³ moles

Also, the atomic mass of manganese is 54.94 g/ mole i.e for 54.94 g you will have a mole of manganese. For 2.026×10³moles, you will have 54.94×2.026×10³ grams= 11.131 ×10⁴grams

1000g =1kg

11.131×10⁴ g = 11.131×10⁴/1000 kg or 111kg of Manganese

d.

There are 1× 5.48×10²⁹/6.022×10²³ moles in 5.48 ×10²⁹ atoms of lithium

This is equal to 9.1×10⁵ moles

Also, the atomic mass of lithium is 6.941 g/ mole i.e for 6.941 g you will have a mole of lithium. For 9.1×10⁵moles, you will have 6.941×9.1×10⁵ grams=63.16×10⁵grams

1000g =1kg

63.16×10⁵ g = 63.16×10⁵/1000 kg or 6.32×10³kg of lithium