Question

your teacher places a clump of iron wool on the scale and lights it on fire. you can see the iron wool has a starting mass of 27.37 grams. after being lit on fire, the mass increases to 29.11 grams. once the iron wool is lit on fire, it cant be lit on fire again. if this entire experiment took place in a closed system on top of the scale (similar to what you see in the image) what would be different? the mass of the iron would decrease. the iron could burn more than once. the mass would stay the same before and after burning. the color would stay the before and after burning.

Explanation:

Step1: Understand the iron - wool burning reaction

When iron wool burns in air, it reacts with oxygen to form iron oxide. According to the law of conservation of mass, in a closed - system, the total mass of the reactants equals the total mass of the products.

Step2: Analyze the mass change

The initial mass of iron wool is 27.37 grams and after burning it is 29.11 grams. The increase in mass is due to the oxygen from the air combining with the iron. If the experiment was done in a closed system, the mass on the scale would remain the same because the oxygen that reacts with the iron is already accounted for within the closed system.

Answer:

The mass would stay the same before and after burning.