Chemistry Semester 1 Exam Review

Front

What is scientific notation?

Back

A way of expressing numbers that are too large or too small to be conveniently written in decimal form, typically in the format a × 10^n, where 1 ≤ a < 10 and n is an integer.

Front

Convert 702.0 g to scientific notation.

Back

7.020 × 10² g.

Front

What is percent by mass?

Back

A percentage determined by the ratio of the masses of each element to the total mass of the compound.

Front

What is the formula to calculate the energy of a photon?

Back

E = hc/λ, where E is energy, h is Planck's constant, c is the speed of light, and λ is the wavelength.

Front

Calculate the energy of a photon with a wavelength of 4.50 x 10⁻⁷ m.

Back

4.42 x 10⁻¹⁹ J.

Front

What is an SI base unit?

Back

A fundamental unit of measurement defined by the International System of Units (SI), such as meter, kilogram, or second.

Front

Which of the following is NOT an SI base unit: meter, pounds, kilogram, second?

Back

Pounds.

Front

What is the law of conservation of mass?

Back

In a chemical reaction, mass is neither created nor destroyed; the total mass of reactants equals the total mass of products.

Front

If 44.6 grams of iron (Fe) combines with 12.8 grams of oxygen (O₂), what is the mass of the product formed?

Back

57.4 grams.

Front

What is molar mass?

Back

The mass of one mole of a substance, usually expressed in grams per mole (g/mol).