How many mole ratios can be written for a chemical reaction involving four substances?

12 and 20 moles ratios, respectively.

Explanation:

Note that the number of mole ratios you can write for a chemical reaction involving a total of n substances is (n)(n–1). Thus, for reactions involving four and five substances, you can write 12 and 20 moles ratios, respectively.

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kuchisake

kuchisake-onna (口裂け女, "slit mouth woman ") is a malevolent figure appearing in japanese ghost stories, possibly dating back to the edo period. she takes the form of a masked woman who approaches people and asks them if they believe she is pretty.

explanation:

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%