1Question
A student has a sample containing 12 g of carbon, 1 g of hydrogen, and 16 g of oxygen. What is the total mass of the sample?
2Question
A cell contains 70% water by mass. If the cell has a mass of 200 g, how much of the cell is water?
3Question
A solution contains 15 g of salt in 300 g of solution. What is the mass percent of salt in the solution?
4Question
A plant leaf sample has 48 g of dry matter and 192 g of water. What percentage of the sample is water?
5Question
A researcher measures 25 mL of ethanol in a 100 mL solution. What is the volume percent of ethanol?
6Question
A compound is made of 3 g of element A and 9 g of element B. What is the mass ratio of A to B in simplest form?
7Question
A pond water sample contains 2 mg of nitrate in 500 mL of water. What is the nitrate concentration in mg/mL?
8Question
A person drinks 250 mL of water, and the water has a density of 1 g/mL. What mass of water did the person drink?
9Question
A cell’s cytoplasm contains 18 g of solute in 162 g of water. What is the total mass of the cytoplasm solution?
10Question
A scientist compares two tissues. Tissue X contains 40% protein and weighs 500 g. How many grams of protein does Tissue X contain?
11Question
A sample of muscle tissue has 300 g of water and 75 g of solids. What fraction of the tissue mass is solid material?
12Question
A student prepares 2 L of a sugar solution containing 80 g of sugar. What is the concentration in g/L?
13Question
A blood sample has a glucose concentration of 90 mg per 100 mL. How much glucose is in 250 mL of blood?
14Question
An enzyme solution contains 12 mg of enzyme in 3 mL. If a technician needs 60 mg, how many milliliters of solution are needed?
15Question
A plant cell gains 20 g of water by osmosis and its initial mass was 180 g. What is its new mass?
16Question
A scientist removes 35 g of water from a 210 g tissue sample. What is the mass of the tissue sample after drying?
17Question
A solution has a concentration of 6% solute by mass. If the total mass is 450 g, how many grams of solute are present?
18Question
A protein sample has a mass of 0.75 kg. How many grams is this?
19Question
A student dissolves 10 g of glucose in enough water to make 250 mL of solution. What is the concentration in g per 100 mL?
20Question
A cell membrane is surrounded by a fluid that contains 8 g of solute in 2 kg of solution. What is the mass percent of solute?
21Question
A lab sample contains 5% sodium chloride by mass. If the sample mass is 1.2 kg, what mass of sodium chloride does it contain?
22Question
A tissue sample contains 0.9 g of lipid in 30 g of tissue. What is the lipid concentration as a percentage by mass?
23Question
A culture medium has 0.15 mol of a nutrient in 3 L. What is the molarity of the nutrient?
24Question
A cell uses 18 kJ of energy to transport 3 mol of ions. How much energy is used per mole of ions?
25Question
A solution has a density of 1.2 g/mL and a volume of 500 mL. What is the mass of the solution?
26Question
A biologist finds that a leaf sample contains 2.4 g of chlorophyll in 800 g of leaf tissue. What is the concentration in parts per thousand (ppt)?
27Question
A cell has 2.5 g of solute in 50 g of cytoplasm. If the cell absorbs 10 g of water, what is the new mass percent of solute in the cytoplasm?
28Question
A scientist prepares a 0.2 M solution using 0.5 L of water and a solute with molar mass 40 g/mol. How many grams of solute are needed?
29Question
A sample of tissue has a dry mass of 18 g and a wet mass of 90 g. What percentage of the tissue mass is water?
30Question
A researcher compares two organ samples. Organ A has 12% protein by mass and a total mass of 750 g. Organ B has 90 g of protein and a total mass of 600 g. Which organ has the higher protein concentration, and by how many percentage points?