Answer:
a. chemical change
Explanation:
A chemical change can cause an odor, however a physical change cannot, and the use of thermal energy will only make an object colder, not give it an odor.
Answer:
mass (m) of the snow that the backpacker collected= 0.855 kg
Explanation:
Given that:
Q = 643 kJ = 643000 J
ΔHfusion = 6.02 kJ/mol = 6020 J/mol
number of mole of water H2O = 
c = 4.18 J/g⋅K
ΔT = 100 K
Since there is a phase change from solid to liquid; then :

ΔH = 
However without the given mass; we substitute
for the number of moles; so:
Q =



m = 855 g
m = 0.855 kg
mass (m) of the snow that the backpacker collected= 0.855 kg
Answer:
When writing equation the mass on left side of equation must be equal to the mass on right side. True
Explanation:
The chemical reactions always follow the law of conservation of mass.
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
Explanation:
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In photosynthesis reaction:
6CO₂ + 6H₂O + energy → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass because total mass is equal on both side of equation.
Answer:
C.) They act as catalysts.
Answer:
See explanation
Explanation:
When we talk about electrophilic substitution, we are talking about a substitution reaction in which the attacking agent is an electrophile. The electrophile attacks an electron rich area of a compound during the reaction.
The five membered furan ring is aromatic just as benzene. This aromatic structure is maintained during electrophilic substitution reaction. The attack of the electrophile generates a resonance stabilized intermediate whose canonical structures have been shown in the image attached.