Chemistry Mid-term Exam 2024

Front

What is the difference between accuracy and precision in measurements?

Back

Accuracy refers to how close a measured value is to the actual (true) value, while precision refers to how close the measured values are to each other.

Front

What is the mass of products in a chemical reaction if the recorded values are 8.83 g, 8.84 g, and 8.82 g?

Back

The mass of products is 8.83 g, which is both accurate and precise.

Front

How many neutrons are in an isotope of Hydrogen-3?

Back

Hydrogen-3 has 2 neutrons.

Front

Where are protons and neutrons located in an atom?

Back

Protons and neutrons are located in the nucleus of an atom.

Front

How do you calculate the mass of a substance from moles?

Back

Mass (g) = Moles x Molar Mass (g/mol). For example, 0.0825 moles of Silver (Ag) is 9.17 grams.

Front

What is scientific notation?

Back

Scientific notation is a way of expressing numbers as a product of a number between 1 and 10 and a power of 10.

Front

How do you add numbers in scientific notation?

Back

Align the powers of ten, add the coefficients, and adjust the result to maintain proper scientific notation.

Front

What is the molar mass of Silver (Ag)?

Back

The molar mass of Silver (Ag) is approximately 107.87 g/mol.

Front

What is an isotope?

Back

An isotope is a variant of a chemical element that has the same number of protons but a different number of neutrons.

Front

What is the formula for calculating the number of neutrons in an isotope?

Back

Number of Neutrons = Mass Number - Atomic Number.