What's the mass of 7.61 x 10^24 molecules of Magnesium sulfate heptahydrate?
1400 g
1900 g
2500 g
31009

Mass = 3100 g

Explanation:

Given data:

Mass of MgSO₄.7H₂O = ?

Number of molecules = 7.61×10²⁴ molecules

Solution:

First of all we will calculate the number of moles of MgSO₄.7H₂O by using Avogadro number.

1 mole contain 6.022×10²³ molecules

7.61×10²⁴ molecules × 1 mol  / 6.022×10²³ molecules

1.26×10¹ mol

12.6 moles

Mass of MgSO₄.7H₂O:

Mass = number of moles × molar mass

Molar mass of MgSO₄.7H₂O = 246 g/mol

Mass = 12.6 mol × 246 g/mol

Mass = 3100 g

that's what i got you can count the number of atoms

each chemical family is represented as a group or column on the periodic table. based on chemical properties, there are 6 types of chemical families. group 1 represents alkali metals, group 2 represents alkaline earth metals, groups 3 to 12 represent transition metals, groups 13 to 16 represent non-metals and other metals, group 17 represents halogens and group 18 represents noble gases.