Question

How will you prepare 500 g of 50% sugar syrup for your fruit preserves?
2. In the formulation of sweet and sour sauce, 20 g cornstarch, 5 g salt, 20 g sugar, 25
g vinegar and 230 g water were used.
a) Find the percentage of each component in the mixture.
b) If you are asked to prepare 5000 g of sweet and sour sauce, how much of each
component will you use?
3. How will you prepare 1 liter of 70% ethanol from 95% by weight ethanol?
4. Five grams of citric acid containing 20% moisture is added to 500 g mango puree.
Find the % citric acid in mango puree mixture.
5. What is the % Ca in 1 mole of CaSO4, CaCl2, and CaCO3?
6. In the quantitative determination of sugars by paper chromatography, the solvent
system being used was n-butanal-pyridine-water at a ratio of 6:4:3. What will be
the volume percent of each component?
7. A solution of NaCl in water contains 230 g of NaCl per liter at 20oC. The density
of the solution at this temperature is 1.148 g/ml while the density of pure water is
0.998 g/ml.
a) Find: a) Weight of NaCl b) Volume of water
8. Cassava tuber has a composition of 57.6% moisture, 6% protein, 0.2% fat, 34.3%
total carbohydrate, 1.6% fiber and 0.3% ash. Find the composition on dry basis.
9. On dry basis, glutinous rice has the following composition.
Protein 8.2%
Total Carbohydrate 90.0%
Fat 1.0%
Fiber 0.2%
Ash 0.6%
What will be the composition in wet basis if the original sample has a moisture content of
11.7%?
10. In a moisture determination 5 g sample was placed in the oven for 24 hours at
100oC. On weighing, the sample gave a reading of 2.4 g. Find the moisture content
of the sample. Find the solid content of the sample.
Part 2. Density and Specific Gravity
1. Five ml of sulfuric acid weighs 9.2 g. Find the specific gravity of sulfuric acid.
2. The specific gravity of ethyl alcohol is 0.789. Find the density.
3. Milk in 1.5 in x 2.5 in x 4 in. in tetrabrick weighs 392 g. Find the density of milk
in g/cc.
4. How much sulfuric acid (specific gravity = 1.18) will you need if you want to
prepare a 500 ml of 5% solution?
Part 3. Gram Molecular Weight or Gram Mole-Molecular Weight of a Substance
1. Calculate the molecular weight of the following compounds:
a) Ca3(PO4)2
b) H2SO4
c) CaHPO4
d) CH2CH2CH2CH2COOH
2. Calculate the number of moles of CaCO3 in 150 g sample of limestone which is
90% pure.
Part 4. Molarity
1. Calculate the molarity of the following solutions:
Wt. of solute Vol. of Soln
6.5 g NaOH 1.2 L.
50.0 g NaCl 450.0 mL.
30.0 g HCl 10.0 mL.
2. Calculate the weight of H2SO4 in 3 liters of 0.2 M solution.
3. How will you prepare 500 ml of 0.2 M H2SO4 from concentrated sulfuric acid
of 98.5% purity with specific gravity of 1.84?
Part 5. Molality
1. A solution of sulfuric acid was made by dissolving 20.0 g of 98% sulfuric acid in
250 ml water. Find the molality of the solution.
2. Find the molality of a solution resulting from the addition of 100 ml of 20% sodium
chloride to 150 ml of 5% NaCl solution. Assume density is 1.1

Answer 1

Answer:

3. to make 70% ethanol from 95% ethanol, take 70 ml of 95% ethanol and add enough water to bring the volume to 95 ml. have 95 ml of 70% ethanol.

7. v= 1 liter

m of Na/L=230g

mols/L= 10

molarity= 10

d=1.148g/cm3

m=%w/w×10×d/M.M

10=%w/w×10×1.148/23

%w/w=23/1.148

=20.03%