C is the answer did y get it right
Answer:
1) rusting of metal is both chemical and physical change
2) black ice is an example of a physical change
Explanation:
when metal rusts, it is due to a reaction between the atoms in the metal and the atoms in the air(oxygen) or water(oxygen). When it rusts it also physically changes the look of the metal from silver to dirty brownish maroon.
Black ice is a change in state hence it cannot be a chemical change as the original substance NO LONGER EXISTS in a chemical reaction. It is a physical change however as the ice is changing into a different state of matter.
HOPE THIS HELPS!!!
C2H2 has 3 bonds between two carbon atoms
Answer:
Tom is correct. The rate of reaction of Crystal violet and NaOH is first order with respect to NaOH, hence, a higher concentration of NaOH corresponds to a higher rate of reaction; a faster reaction.
This means the speed of cleaning depends on the concentration of the lye used.
Explanation:
The reaction between Crystal violet and NaOH, represented as
CV⁺ + OH⁻ → CVOH
It is a reaction that is know to turn the violet colour of the crystal violet colourless.
The rate of the reaction is also known to be second order; first order with respect to Crystal violet and first order with respect to NaOH.
This means that the rate of reaction is directly proportional to the concentration of NaOH provided all other parameters such as the rate constant and the concentration of Crystal violet are constant.
Hence, the reaction becomes faster with an increased concentration of NaOH.
So, Tom is right, concentrated lye solution would remove the stain faster.
Bob is wrong.
Hope this Helps!!!
