0.4M is the concentration of a solution formed when 4.00 grams of sodium hydroxide is dissolved to make a 250cm cubed solution.
Molar concentration, also known as molarity, quantity concentration, or substance concentration. Molarity is a unit used to describe the amount of a substance in a solution expressed as a percentage of its volume. The number of moles per liter, denoted by the unit symbol mol/L or mol/dm³ in SI units, is the most often used unit denoting molarity. Because the volume of most solutions very minimally changes with temperature owing to thermal expansion, using molar concentration in thermodynamics is frequently not practical.
The formula for molarity,
Molarity = (moles/vol) x 1000
= 
x 1000
= (0.1 / 250) x 1000
=0.4M
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Tincture of iodine has antiseptic properties and is made by dissolving iodine crystals in alcohol.
<h3>What are antiseptics?</h3>
Antiseptics are substance which prevent or stops the growth of microorganisms.
Microorganisms have been known to cause diseases, therefore the application of antiseptics are useful to prevent diseases.
An example of an antiseptic is tincture of iodine.
Tincture of iodine is prepared by dissolving iodine crystals in alcohol.
In conclusion, antiseptics are useful in the prevention of diseases by microorganism. An example of an antiseptic is tincture of iodine.
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Answer:
C
Explanation:
The oxidation number of Sulphur in SO4^2- is;
x + 4(-2) = -2
x - 8 = -2
x = -2 + 8
x = 6
Now,
the oxidation number of sulphur in H2SO3 is
2 (1) + x + 3(-2) = 0
2 + x -6 = 0
-4 + x = 0
x = 4
Hence, the oxidation number of sulphur changed from +6 to +4 which signifies gain of two electrons as shown in option C.
Answer:
Total pressure in flask is 2.37 atm.
Explanation:
According to the Dalton's law of partial pressure, the total pressure of the flask would be the sum of partial pressure of the gases present in mixture.
P(total) = P1+ P2+P3+...Pn
n= number of gases present
Given data:
Pressure of argon gas = 0.72 atm
Pressure of oxygen gas = 1.65 atm
Total pressure in flask = ?
Solution:
P(total) = P (argon) + P (oxygen)
P(total) = 0.72 + 1.65
P(total) = 2.37 atm
