Question

a sealed test tube containing 5 grams of iron filings and 10 grams of sulfur is heated until the material in the test tube glows bright red. which is true about the reaction? the mass of the product cannot be determined the product will have a mass more than 15 grams the product will have a mass of 15 grams the product will have a mass less than 15 grams

Explanation:

Step1: Apply the law of conservation of mass

The law of conservation of mass states that mass is neither created nor destroyed in a chemical reaction. In a sealed test - tube (a closed system), the total mass of reactants before the reaction is equal to the total mass of products after the reaction.
The mass of reactants \(m = m_{Fe}+m_{S}\), where \(m_{Fe} = 5\space g\) and \(m_{S}=10\space g\). So, \(m=5 + 10=15\space g\)

Answer:

The product will have a mass of 15 grams.