First, you mix the salt and sand with water, so the salt dissolves. Next, you filter the sand out, so you have the slat water and sand separated. Then, you evaporate the water, leaving the salt behind.
Answer: Common sources of error include instrumental, environmental, procedural, and human. All of these errors can be either random or systematic depending on how they affect the results. Make sure you have your problem, hypothesis, evidence, analyze the data, ask yourself if the evidence supports ur hypothesis, draw conclusions, and communicate your results!
Explanation:
<h2><em>It is True that every bronsted-lowry acid is also a lewis acid </em></h2>
Answer : 50.69 mg of ascorbic acid does not meet the daily requirement.
Solution : Given,
Molar mass of Ascorbic acid = 176 g/mole
Moles of Ascorbic acid = 
Formula used :

or, 
Now put all the given values in this formula, we get the mass of ascorbic acid.

Conversion : 
As per question, a healthy adult’s daily requirement of vitamin C is 70-90 mg. But calculate mass of vitamin C is 50.69 mg. So, 50.69 mg of ascorbic acid does not meet the daily requirement.
The gallionella bacteria reaction
that is Fe2+ → Fe3+ is example of oxidation reaction (answer A)
Explanation
oxidation reaction reaction occurs when electrons are lost during reaction by a molecule or ion or atom. when oxidation occurs the oxidation state of the molecule or ion or atom increases. For this reason Fe2+ → Fe3+ is a oxidation reaction since the oxidation state move from oxidation state 2 to 3