Unit 1
Count the significant figures in 0.00450
What is 3?
A sealed container with ice and bottle has the same mass before and after melting. This statement describes which scientific principle?
What is mass is conserved in a closed system?
True/False: A characteristic property does not change when the amount or shape of a sample changes.
What is True?
“Temperature never affects solubility.” True or false?
What is False — temperature often affects solubility.
Define a heterogeneous mixture and give one example.
What is a mixture with visibly different parts (e.g., oil + water)?
Round 6,482 to 2 significant figures
What is 6,500?
In a dissolve-the-salt-in-water lab, mass before mixing = 28.35 g. After capping and dissolving, what should you expect the mass to be?
What is 28.35 g (unchanged)?
Calculate density: mass = 26.49 g, volume = 3.00 cm³. Give density to appropriate sig figs.
What is 8.83 g/cm³?
Convert concentration: 0.450 g/cm³ salt solution → how many grams of salt for 55.00 mL of water?
What is 24.75 g?
Define (in one sentence): A homogeneous mixture.
What is a mixture with uniform composition throughout (e.g., salt water)?
Add 12.45 + 0.3. Give both the exact sum and the properly rounded answer using significant-figure rules.
What is 12.8?
If the mass after dissolving salt and water is 28.07 g (less than before), give one plausible experimental error that explains the loss.
What is spillage or leakage / the system wasn’t closed (evaporation or salt lost)?
Molar heat capacity is a characteristic property. If 20.0 g of aluminum gives 24.2 J/mol·°C, what happens to the molar heat capacity if you tested a 100.0 g sample? (assume it’s still the same property)
What is it stays the same (molar heat capacity is independent of sample mass)?
A solution has 80.0 g NaNO₃ per 100 mL solvent. The solubility chart shows NaNO₃ solubility at 20 °C is 95 g/100 mL. Is the 80 g solution saturated at 20 °C? Explain.
What is No — it’s unsaturated because 95 g/100 mL is the saturation limit at 20 °C.
What is the difference between filtrate and filtride? One-sentence answer.
What is filtrate is the liquid that passes through the filter; filtride is what’s left on the filter?
You have prices: $8, $12, $14, $17, $11, $9, $13, $22. How many fall in the $10.00–$15.00 interval?
What is 5?
You leave an open bottle of sugar + water overnight; the next day total mass is lower. Which single explanation best fits?
What is some water evaporated into the air?
True/False: The density of a gas can change when temperature or pressure change.
What is True?
The label for the x axis on a Solubility Curve
What is temperature(degrees celsius)?
You need to separate salt + sulfur. Name one simple technique and the property it uses.
What is dissolve the salt in water (salt soluble, sulfur insoluble) then filter and evaporate — property: solubility?
What is frequency?
A student heats copper and sulfur in an open tube (no rubber stopper) and records unexpected mass change. Should this data be included in a “closed-system” class dataset? Explain briefly.
What is No — the system wasn’t closed, so mass may have escaped or entered.
If mercury has density 13.6 g/mL, what is the mass of 275 mL of mercury?
What is 3,740 g?
The label for the Y axis on a Solubility curve
What is Solubility g/100 mL of water?
The separation technique used to separate liquids based on boiling point
What is fractional distillation?