- A chemical equation is balanced when
- the number of atoms of each element is the same in reactants and products.
- A reaction that releases energy as it occurs is classified as an
- exothermic reaction.
- Activation energy is
- the minimun energy needed for a chemical reaction to begin.
- Any reaction that absorbs 150 kcal of energy can be classified as
- endothermic
- Avogadros number is the number of
- particles in 1 mole of a substance
- Burning sugar is a
- chemical change
- Dry ice subliming is a
- physical change
- Griding coffe beans is an example of
- physical change.
- How many grams of barium chloride are needed to make 100. grams of barium sulfate?
- 89.3 g
- How many grams of Fe2O3 are there in 0.500 mole of Fe2O3?
- 79.8 g
- How many moles of K2SO4 are in 15.0 of K2SO4?
- 0.0861 moles
- How many moles of water, H2O are present in 75.0 g H2O?
- 4.17 moles
- In a combination reaction,
- two or more elements or compounds form one product.
- In an oxidation reduction reaction, the substance oxidized always
- shows a loss of electrons.
- In this reaction, what is the coefficient for calcium oxide? CaO + CO2 - CaCO3
- 1
- Loss of electrons or gain of oxygen describes an
- oxidation.
- N2 + O2 - 2NO
- oxidation reduction reaction.
- One mole of helium gas weights
- 4.00 g
- One mole of particles of any substance contains how many particles?
- 6.02 X 10*23
- The following reaction takes place when an electric current is passed through water. It is an example of a _________reaction. 2H2O - 2H2 + O2
- Decomposition
- The molar mass of calcium hydroxide, Ca(OH)2 is
- 74.1 g
- The molar mass of copper II nitrate, Cu(NO3)2 is
- 188 g
- The molar mass of potassium is
- 39.1 g
- The number of moles of oxygen gas needed to react with 4.0 moles of Mg is
- 2.0 moles
- The O-H bond in water is polar because
- Oxygen is much more electronegative than hydrogen.
- What is the classification for this reaction 2C + O2 - 2CO
- combination
- What is the classification for this reaction SO3 + H2O - H2SO4
- Combination
- what is the classification for this unbalanced reaction? Fe + HCL - FeCl3 + H2.
- Single replacement
- What is the correct form to convert the number of O2 to the number of moles of Fe2O3?
- 2 moles FE2O3 / 3 moles O2
- What is the molar mass of copper II sulfate, CuSO4?
- 159.6 g
- What is the molar mass of sucrose (C12H22O11)
- 342 g
- When KCI dissolve is water
- The K+ ions are attracted to the partially neg oxygen atoms of the water molecule.
- When some of the sugar added to iced tea remains undissolved at the bottom of the glass, the solution is
- saturated
