<span>The student should
follow following steps to make 1 L of </span>2.0 M CaCl₂.<span>
<span>
1. First he should
calculate the number of moles of 2.0 M CaCl</span></span>₂ in 1 L solution.<span>
</span>Molarity of the solution = 2.0 M<span>
Volume of solution which should be prepared = 1 L
Molarity =
number of moles / volume of the solution
Hence, number of moles in 1 L = 2 mol
2. Find
out the mass of dry CaCl</span>₂ in 2 moles.<span>
moles =
mass / molar mass
Moles of CaCl₂ =
2 mol</span><span>
Molar mass of CaCl₂ = </span><span>110.98 g/mol
Hence, mass of CaCl</span>₂ = 2 mol x <span>110.98 g/mol
= 221.96
g
3. Weigh the mass
accurately
4. Then take a cleaned and dry1 L volumetric flask and place a funnel top of it. Then carefully add the salt into the volumetric flask and
finally wash the funnel and watch glass
with de-ionized water. That water also should be added into the volumetric
flask.
5. Then add some
de-ionized water into
the volumetric flask and swirl well until all salt are
dissolved.
<span>6. Then top up to
mark of the volumetric flask carefully.
</span></span>
7. As the final step prepared solution should be labelled.
Both of them have high electronegativity. Hence they both tend to gain electrons to gain stability.
Answer:
2. 181.25 K.
3. 0.04 atm.
Explanation:
2. Determination of the temperature.
Number of mole (n) = 2.1 moles
Pressure (P) = 1.25 atm
Volume (V) = 25 L
Gas constant (R) = 0.0821 atm.L/Kmol
Temperature (T) =?
The temperature can be obtained by using the ideal gas equation as illustrated below:
PV = nRT
1.25 × 25 = 2.1 × 0.0821 × T
31.25 = 0.17241 × T
Divide both side by 0.17241
T = 31.25 / 0.17241
T = 181.25 K
Thus, the temperature is 181.25 K.
3. Determination of the pressure.
Number of mole (n) = 10 moles
Volume (V) = 5000 L
Temperature (T) = –10 °C = –10 °C + 273 = 263 K
Gas constant (R) = 0.0821 atm.L/Kmol
Pressure (P) =?
The pressure can be obtained by using the ideal gas equation as illustrated below:
PV = nRT
P × 5000 = 10 × 0.0821 × 263
P × 5000 = 215.923
Divide both side by 5000
P = 215.923 / 5000
P = 0.04 atm
Thus, the pressure is 0.04 atm
Below are the order of the units from largest to the smallest:<span>
m^3 = meters and is 1 meter^3 is equal to 1000 liters
L = Liters and 1 liter is equal to 10 deciliter
dL = decilter, 1 deciliter is equal to 10 centiliter
cL = centiliter, 1 centiliter is equal to 10 mililiter
mL = mililiter, 1 militer is equal to </span><span>1000.000 µl</span>
µl = micorlitre
