Physical or Chemical Change?
Breaking a Glass
Physical change (Breaking a glass changes its shape and size, but the material (glass) remains the same.)
Write the symbol for this ion: the ion with a 1+ charge, atomic number 55, and mass number 133
Cs+
Name the following ionic compound: CuSO4
Copper(II) sulfate
What is the total mass (amu) of carbon in the following molecule? CHCl3
12.01 amu
Balance this equation:
PCl5(s)+H2O(l)⟶POCl3(l)+HCl(aq)
2PCl5(s)+5H2O(l)→2POCl3(l)+10HCl(aq)
Rusting of Iron
Chemical Change (Rusting occurs when iron reacts with oxygen and moisture in the air to form iron oxide (rust), a new substance with different properties.)
Write the symbol for this ion: the ion with a 3+ charge, 28 electrons, and a mass number of 71
Ga3+
Determine the oxidation states of the elements in the following compound: Fe2O3
Oxidation state of Fe = +3
Oxidation state of O = -2
Calculate the molecular or formula mass of Ca(NO3)2
164.10 amu
Balance this equation: Na(s)+H2O(l)⟶NaOH(aq)+H2(g)
2Na(s)+2H2O(l)→2NaOH(aq)+H2(g)
Baking a Cupcake
Chemical Change (During baking, the heat causes ingredients (ex: flour, sugar, eggs) to go through chemical reactions.)
Determine the number of protons, neutrons, and electrons in this isotope: atomic number 9, mass number 18, charge of 1−
Protons: 9
Neutrons: 9
Electrons: 10
Name the following binary molecular compound: PCl3
Phosphorus trichloride
Determine the number of moles in 25.0 g of propylene, C3H6
0.594 moles
Indicate what type (or types) of reaction the following represents:
Ca(s)+Br2(l)⟶CaBr2(s)
Synthesis and Redox Reaction
Leaves changing color
Chemical Change (Leaves change color because the green pigment (chlorophyll) breaks down as the tree prepares for winter. As the green fades away, other colors (yellow, red) appear because different pigments in the leaf are revealed. This involves chemical reactions)
Determine the number of protons, neutrons, and electrons in this isotope: atomic number 43, mass number 99, charge of 7+
Protons: 43
Neutrons: 56
Electrons: 36
Name the following acid, which is dissolved in water: H2SO4
Sulfuric acid
Determine the mass of 0.0146 mol KOH
0.819 grams
Determine the oxidation states of the elements in the compound: GdCl3
Gd (gadolinium) has an oxidation state of +3.
Cl (chlorine) has an oxidation state of -1.
Boiling water to produce steam
Physical Change (Boiling water is a change in state from liquid to gas (water to steam). The chemical composition of water (H₂O) remains the same, so it is a physical change.)
Determine the number of protons, neutrons, and electrons in this isotope: B510
Protons: 5
Neutrons: 5
Electrons: 5
Write the chemical formula for phosphoric acid.
H3PO4
A 55-kg woman has 7.5 × 10^−3 mol of hemoglobin (molar mass = 64,456 g/mol) in her blood. How many hemoglobin molecules is this?
4.52 × 10^21 molecules
Gallium chloride is formed by the reaction of 2.6 L of a 1.44 M solution of HCl according to the following equation: 2Ga+6HCl⟶2GaCl3+3H2.
Determine the number of moles and mass of gallium chloride.
Moles of GaCl3 = 1.872 mol
Mass of GaCl3 = 329.7 g