Volume percent<span> or </span>volume/volume percent<span> (v/v%) is used when preparing solutions of liquids. It will have units of volume of the smaller composition substance over the volume of the solution. We calculate as follows:
12.5 mL ethanol = .225 mL ethanol / 1 mL solution ( V )
V = 55.56 mL of the 22.5 % by volume ethanol solution is needed
Hope this answers the question.</span>
Answer:
option A= Physical change
Explanation:
physical change:
" It is a change in which no new substance is formed"
Breaking of object like glass is the example of physical change because it is not change into another object. It effect the form of object but can not change the chemical composition.
Chemical changes:
" it is a change in which one substance is converted into new product through chemical reaction".
During the chemical changes the types and the number of atom remain same but their arrangement changed.
for example: burning of wood, baking of cake, digesting food, resting of iron etc.
Physical reaction:
" physical reaction occur during the molecular rearrangement. There is no chemical change occur"
In this type of changes no bonds are break to form new bonds, for example boiling point.
Chemical reaction:
" chemical reaction occur when molecules are chemically react with each others and bonds formation and breaking is also occur"
Answer:
Mean rate of reaction produced = 0.533 g/sec (approx.)
Explanation:
Given:
Reaction produced = 1.6 gram
Time taken = 30 sec
Find:
Mean rate of reaction produced
Computation:
Mean rate of reaction produced = Reaction produced / Time taken
Mean rate of reaction produced = 1.6 / 30
Mean rate of reaction produced = 0.533 g/sec (approx.)
Answer: Sodium
Explanation: The sodium has only one electron at the outer layer.
Hope this helps! :)
Answer:
D
) feedback
Explanation:
When we use an air conditioner, it get turn off when reaches its required temperature and when the house warm up the air conditioning unit turns on again, that is an example of feedback.
The given condition is an example of negative feedback because in negative feedback, any change in the input is opposed by generating an output. Here also, warming up of house (change in one direction) allows the air conditioning unit turns on and it gives cool air (opposing that change).
Hence, the correct option is "D".
