Balancing equations
Balance the following equation: S8+O2--> SO2
S8+8O2--> 8SO2
X+Y--> XY represents this type of chemical equation.
What is a synthesis reaction?
Change in color, temperature, texture etc..
Name three things that can impact the rate of a chemical reaction.
What are temperature, surface area, concentration, catalyst and pressure?
The ________ of Conservation of Mass.
Choices: Hypothesis, Theory or Law
What is Law?
Balance the following equation: N2+H2-->NH3
N2+ 3H2--> 2NH3
What is the difference between an endothermic and an exothermic reaction?
In an endothermic reaction, the reactants have less energy than the products and in an exothermic reaction the reactants have more energy than the products.
Endothermic reactions feel_______ (hot or cold)?
Cold
What is a catalyst?
A catalyst is a substance that causes or accelerates a chemical reaction without itself being affected.
The Law of Conservation of Mass states this.
What is that matter is neither created nor destroyed but can change form.
Balance the following equation: Mn(NO2)2+BeCl2-->Be(NO2)2+ MnCl2
Mn(NO2)2+BeCl2-->Be(NO2)2+ MnCl2
NH4NO3(s) + heat--> NH4+(aq)+ NO3-(aq) is endothermic or exothermic?
Endothermic reaction:
You can see, heat is absorbed during the above reaction, lowering the temperature of the reaction mixture, and thus the reaction flask feels cold.
Which of the following is a chemical reaction?
Using the ideas of collision theory, why does decreasing the pressure of something decrease the rate of reaction?
Less pressure, less movement, less likely that molecules will bump into each other.
10 g of a solid chemical reacts with a 10 g of a liquid chemical, the reaction bubbles and changes the color of the liquid. The colored liquid weighs 13 g, what can be concluded?
The gas produced weighed 7 g
Balance the following equation: C2H4O2+O2--> CO2+H2O
C2H4O2+ 2O2--> 2CO2+2H2O
CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g) is an example of this type of chemical equation.
What is a combustion reaction?
Fill in the blanks (WITHOUT a word bank)
The fuel for the space shuttle is hydrogen, which burns in oxygen to produce water vapor and energy. In this chemical reaction, hydrogen is a _____________________, oxygen is a _____________________, and water vapor is a ______________________. In a chemical equation for this reaction, a(n) ___________________ is used to separate the hydrogen and oxygen from water vapor and energy. A(n) ___________________ is used to separate the symbols for hydrogen and oxygen.
The fuel for the space shuttle is hydrogen, which burns in oxygen to produce water vapor and energy. In this chemical reaction, hydrogen is a reactant, oxygen is a reactant, and water vapor is a product. In a chemical equation for this reaction, a(n) yield sign is used to separate the hydrogen and oxygen from water vapor and energy. A(n) plus sign is used to separate the symbols for hydrogen and oxygen.
Collision theory means this.
Collision theory notes that with increased temperature, pressure, surface area, catalyst and concentration, the molecules are more likely to bump into each other and therefore react.
You bake cookies but they loose mass. Explain this using the Law of Conservation of Mass.
The baking soda reacts and releases gas. No matter is lost it just goes into the air around it.
Balance the following chemical equation: H2SO4+B(OH)3--> B2(SO4)3+H2O
3H2SO4+2B(OH)3--> B2(SO4)3+ 6H2O
Elephant toothpaste is an example of this type of reaction. The yeast is called the _________.
What is decomposition reaction? And what is the catalyst?
Tell me the correct type of reaction for each definition
___________ : a substance breaks down into simpler substances
___________ : one element replaces another in a compound
___________ : a hydrocarbon burns in air and forms water and carbon dioxide
___________ : two compounds break apart and switch ionic partners
___________ : two or more substances combine to form a more complex substance
1) Decomposition
2) Single replacement reaction
3) Combustion
4) Double replacement reaction
5) Synthesis reaction
For the following four scenarios, give me the factor that you are changing and how it impacts the rate of the reaction
1) Blowing air on a camp fire to get it going.
2) A Woolly Mammoth is found, perfectly preserved, near the Arctic circle.
3) Raw carrots are cut into thin slices for cooking.
4) Putting yeast into our elephant toothpaste decomposition reaction.
1) Concentration of oxygen increases as you move air around.
2) Lowering the temperature decreases the rate that decomposing reactions occur at and therefore decreases the speed of biological decomposition.
3) More surface area of the whole carrot will touch the hot pan and therefore the carrot as a whole will cook faster.
4) Catalyst- Yeast helps begin the break down of hydrogen peroxide but is not damaged in the process.
Why do we balance chemical equations? Why do we only use coefficients?
Because we need to have the same number of atoms on either side of the equation- we cannot gain or lose atoms through the process of the reaction. We cannot change subscripts because those tell us about the molecules and we cannot change those in the reaction without changing the reality (chemistry and physics) of the equation.