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
Answer:
Boiling point
Explanation:
Distillation is one of the most widely used separation technique in chemistry. It is used to separate a mixture of liquid substances with different boiling point. Hence, the basis of the separation is BOILING POINT DIFFERENCE.
In the procedure, the liquid substances are heated until they turn gaseous, which they do at different times considering their different boiling points. The separated components are then converted back to liquid states in a process called CONDENSATION.
VOLUME= 5cm*10cm*2cm =100cm^3
but density of iron=7.874g/cm^3
mass=7.874g*100 =787.4g
mass of that block = 787.4g
Multiply .800 moles of O2 by Avagadro's number divided by 1 mole. This will get rid of the moles on the bottom and leave you with molecules. So technically .800 times 6.02x10^23.
Nit<u>ITE</u><u /> is NO<u>2</u><u />
nitr<u>ATE</u><u /> is NO<u>3</u><u />
