Calculate the mass of forsterite that contains a million oxygen atoms. Be sure your answer has a unit symbol if necessary, and round it to significant digits.

The  mass of forsterite that contains a million oxygen atoms is 5.67 × 10^-17 g.

The chemical formula of forsterite is Mg2SiO4. Now, molar mass of forsterite is; 2(24) + 28 + 4(16) = 140 g/mol

Next, we have to obtain the number of oxygen atoms that are found in 1 mole of forsterite  as follows;

Number of oxygen atoms in 1 mole = 1 × 4 × 6.02 × 10^23 = 24.08  × 10^23 atoms

Now;

If 1 mole of forsterite  contains 24.08  × 10^23 atoms oxygen atoms

x moles of  forsterite  contains 1 × `10^6 atoms

x =  1 mole × 1 × `10^6 atoms/24.08  × 10^23 atoms

x = 4 × 10^-19 moles

Mass of forsterite that  contains  a million oxygen atoms = 4 × 10^-19 moles

×  140 g/mol = 5.67 × 10^-17 g

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2.33×10¯¹⁶ g of forsterite

Explanation:

From Avogadro's hypothesis, we understood that 1 mole of any substance contains 6.02×10²³ atoms. This equally means that 1 mole of forsterite (Mg2SiO4) contains 6.02×10²³ atoms.

1 mole of forsterite (Mg2SiO4) = (24×2) + 28 + (16×4)

= 48 + 28 + 64

= 140 g

Finally, we shall determine the mass of forsterite that contains a million oxygen atoms.

140 g of forsterite (Mg2SiO4) contains 6.02×10²³ atoms.

Therefore, Xg of forsterite (Mg2SiO4) will contain 1×10⁶ atoms of oxygen i.e

Xg of forsterite (Mg2SiO4) =

(140 × 1×10⁶) /6.02×10²³

= 2.33×10¯¹⁶ g

Therefore, 2.33×10¯¹⁶ g of forsterite contains a million oxygen atoms..

the volume increases

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.