Explanation:
1)

Mass of NaOH = m
MOlar mass of NaOH = 40 g/mol
Volume of NaOH solution = 1.00 L
Molarity of the solution= 1.00 M


A student can prepare the solution by dissolving the 40. grams of NaOH in is small volume of water and making that whole volume of solution to volume of 1 L.
Upto two significant figures mass should be determined.
2)
(dilution equation)
Molarity of the NaOH solution = 
Volume of the solution = 
Molarity of the NaOH solution after dilution = 
Volume of NaOH solution after dilution= 


A student can prepare NaOH solution of 1.00 M by diluting the 0.500 L of 2.00 M solution of NaOH with water to 1.00 L volume.
Upto three significant figures volume should be determined.
H2O means water, which is made of two hydrogen and one oxygen atoms.
Oxygen is a gas that your body needs to function. Oxygen comes from the air.
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Regarding the bonds in FesO₄, Fe and S have an ionic bond, while S and O have covalent bonds.
Elements form bonds to increase their stability. The main types of bonds are:
- Metallic bonds: they are formed between metals and the electrons are in a delocalized cloud.
- Ionic bonds: they are formed between metals (lose electrons) and nonmetals (gain electrons)
- Covalent bonds: they are formed between nonmetals, which share electrons.
Regarding the bonds in FesO₄:
- Fe is a metal and S a nonmetal, thus they will form ionic bonds.
- S and O are both nonmetals, thus they will form covalent bonds.
Regarding the bonds in FesO₄, Fe and S have an ionic bond, while S and O have covalent bonds.
Learn more: brainly.com/question/23882847
We know that density = mass /volume
so
mass=volume*density
volume=mass/density
so c is wrong
Answer: 4.22 grams of solute is there in 278 ml of 0.038 M 
Explanation:
Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.
where,
n = moles of solute
= volume of solution in L
Now put all the given values in the formula of molality, we get

mass of
= 
Thus 4.22 grams of solute is there in 278 ml of 0.038 M 