Answer: To be able to not forget what have they done when they want to re-do it.
to make it easier for the next person to re-do the experiment.
Explanation:
the description of the procedure ensures that when the experiment becomes of a success,specific steps are recorded for improvement of the experiment if maybe the experiment can be done at a short space of time.
Answer:
The substance is a mixture because it left a white powder in the beaker when boiled.
Explanation:
Answer: 2.71 moles of solute for every 1 kg of solvent.
Explanation: As you know, the molality of a solution tells you the number of moles of solute present for every 1 kg of the solvent.This means that the first thing that you need to do here is to figure out how many grams of water are present in your sample. To do that, use the density of water.500.mL⋅1.00 g1mL=500. g Next, use the molar mass of the solute to determine how many moles are present in the sample.115g⋅1 mole NanO385.0g=1.353 moles NaNO3So, you know that this solution will contain 1.353moles of sodium nitrate, the solute, for 500. g of water, the solvent.In order to find the molality of the solution, you must figure out how many moles of solute would be present for 1 kg=103g of water.103g water⋅1.353 moles NaNO3500.g water=2.706 moles NaNO3You can thus say that the molality of the solution is equal to molality=2.706 mol kg−1≈2.71 mol kg−1 The answer is rounded to three sig figs.
Answer:
A chemical reaction happens when substances break apart or combine to form one or more new substances.
Explanation:
hope its right.
Its condensation
the vapour has a lot of kinetic energy but if it cools down it loses that energy and condenses into a liquid
hope that helps
