Book problem E15

[Earl Garrovillo 2L]

E.15 The molar mass of the metal hydroxide M(OH)2 is 74.10g⋅mol−1. What is the molar mass of the sulfide of this metal?

The notation kind of confused me but is it basically saying that "M" is an arbitrary element? And to solve you would just subtract the molar mass of the (OH)2 and add the molar mass of sulfur instead?

[Vivian Hoang 1H]

Hi.

Yes, M is the mystery element!

So you need to find out what it is first by subtracting masses of hydrogen and oxygens from the molar mass that they give you. You will find an element with a molar mass relatively close to the one you find. Then you will use the mystery element you just found to solve for the molar mass of the metal sulfide...

Hope that helps.

[Ryan Laureano 3I]

M is a mystery metal which you need to find by looking at its molar mass. Subtract the molar mass of OH from the compound and you would get the molar mass of M. Then correspond that molar mass to an existing element on the periodic table. Lastly add the molar mass of Sulfide which is S^2. Hope that helps!