Answer:
1 M
Explanation:
The molarity of a solution, M, is a measure of the concentration of that solution and it refers to the number of moles of solute (mol) per liter (L) of solution. The molarity (M) can be calculated using the formula:
M = number of moles (n) /volume (V)
In this question, a 500 ml aqueous solution of Na3PO4 was prepared using 82g of the solute.
Molar mass of Na3PO4 = 23(3) + 15 + 16(4)
= 69 + 31 + 64
= 164g/mol
Mole = mass/molar mass
mole = 82/164
mole = 0.5 mol
Volume in Litres (L) = 500 ml ÷ 1000 = 0.500L
Therefore, Molarity (M) = 0.5/0.500
Molarity = 1 M or 1 mol/L
There is no question on here lol
Democritus developed the atomic model. He theorized that atoms were specific to the material which they composed. He also believed that the atoms different in size and shape, were in constant motion in a void, collided with each other; and during these collisions, could stick together.
<u>Ans: 650 J = 155 calories</u>
<u>Given:</u>
Energy in joules = 650 J
<u>To determine:</u>
The energy in calories
<u>Explanation:</u>
1 joule = 0.2388 calories
Therefore, 650 joules = 0.2388 calories * 650 J/1 J = 155 calories
Answer:
Example
0.5 mol of sodium hydroxide is dissolved in 2 dm3 of water. Calculate the concentration of the sodium hydroxide solution formed.
Concentration =
Concentration = 0.25 mol/dm3
Volume units
Volumes used in concentration calculations must be in dm3, not in cm3. It is useful to know that 1 dm3 = 1000 cm3. This means:
divide by 1000 to convert from cm3 to dm3
multiply by 1000 to convert from dm3 to cm3
For example, 250 cm3 is 0.25 dm3 (250 ÷ 1000). It is often easiest to convert from cm3 to dm3 before continuing with a concentration calculation.
Question
100 cm3 of dilute hydrochloric acid contains 0.02 mol of dissolved hydrogen chloride. Calculate the concentration of the acid in mol/dm3.
Reveal answer
Converting between units
The relative formula mass of the solute is used to convert between mol/dm3 and g/dm3:
to convert from mol/dm3 to g/dm3, multiply by the relative formula mass
to convert from g/dm3 to mol/dm3, divide by the relative formula mass
Remember: the molar mass is the Ar or Mr in grams per mol.
Example
Calculate the concentration of 0.1 mol/dm3 sodium hydroxide solution in g/dm3. (Mr of NaOH = 40)
Concentration = 0.1 × 40
= 4 g/dm3
