Test tube of ammonium chloride (NH4Cl) being heated over a bunsen burner flame. Ammonium chloride decomposes readily when heated, but condenses in the cooler area at the top of the test tube. This is a reversible reaction, where the ammonium chloride decomposes into the gases ammonia (NH3) and hydrogen chloride (HCl).
Answer:
fe3o4+4h2 - 3fe + 4h2o
therefore coefficient is 4
PV / T = P'V' / T'
V = V'
P / T = P' / T'
P = 630 mmHg
T = 100 K
P' = 1760 mmHg
T' = ?
630 / 100 = 1760 / T'
T' = 1760 / 6,3
T' = 279,36 K
T' ≈ 280 K
Physical change: a change in which no new substances are formed. the form of the substance is changed but not it's chemical composition (ice melting, bread toasting)
chemical change: any change that results in the formation of new chemical substances. this type of change modifies molecules and atoms by making and breaking the bonds between atoms! (iron rusting, gas burning)
so basically a physical change just changes the appearance of a substance, but a chemical change changes the makeup on a molecular level. i hope this helps you out!
