The Periodic Table
The element with the smallest mass on the periodic table.
What is hydrogen?
A pure substance consisting only of atoms with the same number of protons in their nuclei
What are elements?
A law that states matter cannot be created or destroyed
What is the law of conservation of mass?
One tablet of ibuprofen, Advil, is 200 mg. One tablet contains 150 mg C, 32 mg O, and 18 mg H. What is the mass percent of each element in one tablet of ibuprofen?
C - 75%
O - 16%
H - 9%
A mixture that is not uniform in composition
A metalloid with an atomic mass of roughly 74.92 amu.
A substance that forms when 2 or more elements come together
A law which states that chemical compounds always form in fixed whole number ratios.
What is the law of definite proportions?
Compound A: 230 g N / 270 g O
Compound B: 225 g N / 525 g O
Determine the mass ratio for compounds A and B. How do they compare?
Compound A has an N:O mass ratio that is 2x that of Compound B
All types of these are made of 2+ pure substances, are not chemically joined, and can be separated by physical processes.
What are mixtures?
What is Xenon?
They require a chemical change to form
What are compounds?
A law that states that two elements combine in multiple ratios to form more than 1 compound.
Citric acid is the acid that gives citrus its distinct sour taste. The chemical formula for citric acid is C6H8O7. A 300 mg sample of citric acid contains 12.0 mg H, 114.0 mg C, and 174 mg O. What is the mass percent of each element in citric acid?
C - 38%
H - 12%
O - 58%
These are difficult to separate, but often fractional distillation can be used a separate them.
What are homogenous mixtures?
This element contains 47 protons and has an average atomic mass of roughly 107.87 amu.
What is Silver?
Substances that cannot be broken down by physical or chemical means
What are pure elements?
A law that states that at a constant temperature and pressure, gasses with the same volume will contain the same number of particles.
What is Avogadro's law?
Compound A: 10.902 g Sn / 2.898 g O
Compound B: 78.848 g Sn / 10.752 g O
Determine how the O/S mass ratios compare and find the formula for each compound.
Compound A has a mass ratio twice the size of Compound B. Compound A has the formula SnO2 and Compound B has the formula SnO.
These are uniform in composition throughout the mixture
What are homogeneous mixtures?
An Alkali Earth Metal that has an atomic mass of roughly 137.33 amu
What is Barium?
These always form in fixed ratios
What are compounds?
A model that states all matter is made of atoms, all atoms of an element are identical, compounds are combinations of two or more elements, and chemical reactions are rearrangements of atoms.
What is Dalton's model of the atom?
Sucrose has a chemical formula of C12H22O11. Sucrose contains 42.11% C, 6.48% H, 51.41% O. A 849 g sample of an unknown sugar is analyzed and found to contain 376.46 g C, 57.93 g H, and 459.61 g O. Is this unknown sample sucrose? Why or Why not?
Yes, the unknown substance is sucrose. We know this because they have the same mass percent. Based on the law of definite proportions any compound with this exact ratio of C:H:O will be sucrose.
These may separated using filtration.
What are heterogeneous mixtures?