1. molarity = (moles)/vol in litres
0.5=[(weight/40)*1000]/4
0.5 = weight/16
weight of NaOH = 8 grams
2. weight = 0.45*850*84/100 gms
molecular weight = 85m (not sure abt this)
The correct answer is:Some substances keep the same molecular structure when they break down, and others do not.
Some substances change their form when they dissolve and some do not. Dissolution can sometimes be regarded as a sort of reaction between a chemical substance and water.
Usually, we can consider dissolution of a substance in water as a sort of chemical reaction for some substances. For instance, an ionic substance interacts with water to form ions. similarly, some salts become hydrolysed in water and give acidic/basic solutions as result of that.
However, some substances do not interact with water upon dissolution. They rather remain as molecular entities because they are not composed of ions.
We can see that some substances keep the same molecular structure when they break down, and others do not keep the same molecular structure when they dissolve hence it is difficult to classify dissolving as a physical or a chemical change.
brainly.com/question/1161517
The compound may or may not be poisonous, depending on the chemical properties of the new substance.
The answer is A. Plasmodesmata. It's a narrow pathway between cells.
The question is incomplete, here is the complete question:
A bottle of rubbing alcohol having aqueous solution of alcohol contains 70% (v/v) alcohol. If Carl buys a 946 ml bottle of rubbing alcohol, how much of the aqueous solution is water?
<u>Answer:</u> The amount of water present in the given bottle of rubbing alcohol is 283.8 mL
<u>Explanation:</u>
We are given:
Volume of bottle of rubbing alcohol = 946 mL
70% (v/v) alcohol solution
This means that 70 mL of rubbing alcohol is present in 100 mL of solution
Amount of water present in solution = [100 - 70] = 30 mL
Applying unitary method:
In 100 mL of solution, the amount of water present is 30 mL
So, in 946 mL of solution, the amount of water present will be = 
Hence, the amount of water present in the given bottle of rubbing alcohol is 283.8 mL
