the sand, salt, and water from each other?
(1) Evaporate the water, then filter out the salt.
(2) Evaporate the water, then filter out the sand.
(3) Filter out the salt, then evaporate the water.
(4) Filter out the sand, then evaporate the water.
Answer is (4).
Explanation:
The given mixture contains an insoluble solid and an aqueous solution of salt. The insoluble solid is sand.
First we have to separate insoluble solid. Sand can be separated by doing filtration. When we filter the mixture sand can be seen as the residue on the filter paper.
After filtering the mixture, we should collect the filtrate. Filtrate is the salt solution. By doing evaporation we can get the solid salt.
First and second choices are wrong because after evaporating water filtrationcannot be done and salt and sand will be mixed together.
Salt cannot befiltered out because the salt is soluble and it is inaqueous medium. Hence, third choice is wrong
(1) HCl (3) NH3
(2) H2O (4) CH4
Answer:
(4) CH4
Explanation:
When there are no polar bonds in a molecule, there is no permanent charge difference between one part of the molecule and another, and the molecule is nonpolar.
In option A, HCl is not nonpolar because Cl has a pretty high electronegativity of 3.16, the H-Cl bond is polar due to the electronegative difference. This means option A is wrong.
In option B, A water molecule is polar because (1) its O-H bonds are significantly polar, and (2) its bent geometry makes the distribution of those polar bonds asymmetrical. The side of the water molecule containing the more electronegative oxygen atom is partially negative, and the side of the molecule containing the less electronegative hydrogen atoms is partially positive.
In option C, NH3 is polar because it has 3 dipoles that do not cancel out. Each N-H bond is polar because N is more electronegative than H. NH3 is overall asymmetrical in its VSEPR shape, so the dipoles don't cancel out and it is therefore polar.
In option D, CH4 looks like a C in the middle with 4 H's coming off of it. It is nonpolar because the electronegative difference is balanced. The H's all have the same electronegativities, and all cancel out since they are opposite one another.
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Links are reported
Answer:
the first one
Explanation:
I take this subject
B. a decrease in greenhouse gases
C. average decrease in the temperatures near Earth's surface
D. a decrease in carbon dioxide emissions
Answer: The correct answer is A. average increase in the temperatures near Earth's surface
Explanation: The reason this is correct is that global warming is it getting hotter, logically the temperatures near Earth's surface will be getting hotter as well. Hope this helps
Vinegar (acetic acid solution) is a polar substance, whereas olive oil is non polar in nature. Like dissolves like. A polar substance cannot dissolve in a non polar compound. Therefore, vinegar which is polar is not soluble in olive oil, a non polar substance. Hence, in a salad dressing olive oil separates out from vinegar.
Added salt would dissolve in vinegar solution as salt, a polar substance which is chemically, sodium chloride is an ionic substance. It can dissolve in the polar vinegar solution but not olive oil.