Question

There are four sketches below. The first sketch shows a sample of Substance X. The three sketches underneath it show three different changes to the sample. You must decide whether each of these changes is possible. If a change is possible, you must also decide whether it is a physical change or a chemical change. Each sketch is drawn as if the sample were under a microscope so powerful that individual atoms could be seen. Also, you should assume that you can see the entire sample, and that the sample is in a sealed box, so that no matter can enter or leave. Sample of Substance x Change 1 Change 3 Change 1 is impossible a physical change a chemical change Change 2 is: impossible a physical change a chemical change Change is impossible a physical change a chemical change x S ?

help, please!

Answer 1

Original sample observations - Closed system 12 molecules say, molecular formula is R₂B Change I (a Red end pouts and 1 Black between part) i No. of molecules = 12 Change 2 Change = only position and orientation No. of molecules = 12 Change = chemical of molecules changed. formula changed formule = RB Formula = same R₂B Equation = 12 RB - 12 RB so it is possible • it is impossible because the number of physical change atoms is not conserved here. 12 R . (no chemical reaction) atoms are missing after the change Change 3 No. of molecules = 18. Change = Identity of molecules changed by some chemical reaction. Formula - 6 R and 12 RB 12R, B Equation = 6R + 12 RB (No. of atoms are conserved after change) so, it is possible and chemical change