Answer:
The pure crystals were soluble in the wash solvent.
Explanation:
The pure crystals on the funnel dissolved because they were soluble in the solvent used for washing. They were carried into the filter flask by the solvent.
The correct answers are options C, that is, silver tarnishes and becomes black when exposed to oxygen, and option E, that is, diesel fuel burns when it is heated.
Chemical changes refer to the modifications in which the chemistry at molecular level is modified as the initial substance gets transformed into a new and different final substance. This change occurs with the dissociation of old bond and production of new bonds respectively.
Silver gets tarnished and becomes black when exposed to oxygen. This refers to a chemical change as silver a white and lustrous substance gets transformed into a tarnish black final substance. However, silver does not easily react with oxygen at usual circumstances. It easily reacts with sulfur comprising components in the air and generates black compound as Ag₂S.
Burning of diesel fuel when it is heated. Diesel refers to a mixture of hydrocarbons varying approximately from C₁₀H₂₀ to C₁₅H₂₈. When these hydrocarbons get burnt they generate novel substances, that is, carbon dioxide and water. Hence, it is also a chemical reaction.
Answer: The density of Ammonia is 0.648 g/l
Explanation:
Density = Mass/ Volume
Mass of one mole of Ammonia (NH3) = 17.031g
Volume =?
Using the ideal gas law we can determine the volume.
PV = nRT
P = 0.913 atm, V= ?, n = 1, R = 0.08206 L.atm/K, and T= 293K
Make V the subject of the formular, we then have;
V= nRT/ P = 1 mol x 0.08206 L.atm/ K.mol x 293 / 0.913 atm
V = 24.04358/ 0.913 = 26.3L
Having gotten the value of Volume in this question, we then go back to solve for density.
Density = Mass/ Volume
17.031g/ 26.3L = 0.64756 ≈ 0.648 g/l
Answer: D. a structure that provides a specific service within a cell
Explanation:
Answer:
it's a poison used to kill people in old times sry if it's wrong
Explanation:
