Stoichiometry, Conversions & Exam Prep Review

These flashcards review molar conversions, stoichiometry, limiting/reactant concepts, percent yield, key formulas, metric prefixes, periodic trends, and exam strategies highlighted in the lecture notes.

What is the molar mass of HNO₃ used in stoichiometry problems?

63 g mol⁻¹

In the balanced reaction producing HNO₃ from MO₂, what is the mole ratio of MO₂ to HNO₃?

3 mol MO₂ : 2 mol HNO₃

What three steps convert 1.0 mol of MO₂ to grams of HNO₃?

Start with moles of MO₂ → apply the 3:2 mole ratio → multiply moles of HNO₃ by 63 g mol⁻¹ to find grams.

Why should you cancel units step-by-step in dimensional analysis?

To verify that units properly convert and the final answer has the correct dimensions, preventing calculation errors.

What coefficient-related mistake must be avoided in stoichiometry?

Using reaction coefficients more than once (double-counting them).

How do you select the correct number of significant figures for an answer?

Match the least number of sig figs given in the problem’s measured values, not the extra digits in conversion factors.

Define the limiting reactant.

The reactant that is completely consumed first, limiting the amount of product formed.

Define the excess reactant.

The reactant that remains after the limiting reactant is used up.

Give the formula for percent yield.

Percent yield = (actual yield ÷ theoretical yield) × 100 %.

Calculate the percent yield for an actual yield of 72.4 g and a theoretical yield of 88 g.

≈ 82.3 %

When no reactant is labeled ‘excess,’ how do you find the limiting reactant?

Convert each reactant to moles of product; the one that produces less product is limiting.

State the density formula.

D = m ⁄ v

State the heat equation involving specific heat capacity.

Q = m × c × ΔT

Name five common metric prefixes useful for unit conversions.

Mega, kilo, centi, milli, micro

What physical states do most metals and most nonmetals have at room temperature?

Most metals are solids; most nonmetals are gases.

Which halogen is a solid at room temperature, making it an exception among nonmetals?

Iodine

How does ionization energy trend across the periodic table?

It increases moving up a group and across a period toward fluorine.

List two calculation types expected on the chemistry midterm.

(Any two) Significant-figure calculations, unit conversions, formula weights, or compound naming/formula writing.

Why does grading emphasize showing all units and labels in each step?

It demonstrates understanding, allows partial credit, and makes the work easy to follow.

What collaboration advice is given for studying chemistry problems?

Study together for support, but ensure you can independently reproduce every step.

When choosing significant figures, should you follow the digits in conversion factors or the given data?

Follow the sig figs in the given data (problem statement).

What reference material is permitted during exams even without internet access?

A periodic table (element data, but no outside websites).

Distinguish between actual yield and theoretical yield.

Actual yield is the amount of product obtained experimentally; theoretical yield is the calculated maximum possible amount.