The unbalanced equation below represents the reaction between silver sulfide and aluminum.

NY Regents Chemistry Exam August 2023 Questions 56-58

Ag2S + Al → Ag + Al2S3

56 Balance the equation in your answer booklet for the reaction, using the smallest whole number coefficients.

Solution: 3Ag2S + 2Al → 6Ag + Al2S3

57. Determine the gram-formula mass of the aluminum sulfide product.

Solution: Al2S3

Al = 2*26.98

S = 3*32.065

Al2S3 = 2*26.98+3*32.065= 150g/mol

58. Show a numerical setup for calculating the number of moles of silver sulfide in a 546-gram sample of Ag2S (gram-formula mass = 248 g/mol).

Solution: According to the Table T on the Reference Table, number of moles = given mass/gram formula mass

number of moles = 546g/(248g/mol)

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Past Exams and Questions: HERE

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