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Hint
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Answer
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what colour is hydrochloric acid solution
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colourless
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in what environment will a reversible reaction always reach dynamic equilibrium
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closed system
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if a reversible reaction is exothermic one way what will the other way be
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endothermic
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what poisonous gas is produced during the reaction between sodium thiosulfate and hydrochloric acid and how do we prevent getting harmed
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sulfur dioxide is produced which dissolves in water to give an acidic solutionof sulfurous acid. The reaction is carried out in a well ventilated room so we don't get harmed.
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what one thing do reactions need to take place
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activation energy
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what is the unit cm³ the same as
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grams
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9999999999999999999
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what is the enthalpy change
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change in heat during a reaction at constant pressure
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what is △H measured in usually
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kJ/mol
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state the word equation in the thermal decomposition of ammonium chloride
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ammonium chloride ⇌ nitrogen + hydrogen chloride
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what will happen if you carry out the calcium carbonate and hydrochloric acid experiment but with bigger marble chips with a total mass of the same before, like you have joined the smaller marble chips together
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these bigger marble chips have a smaller surface area, so reaction will be slower. The same carbon dioxide is produced as it has the same mass, but it takes longer for it to reach the maximum carbon dioxide produced. So it takes longer for the line to plateau or become flat. It is less steep to begin, showing it's slower than before.
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does forming bonds need energy
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no
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what is specific heat capacity
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the amount of energy needed to heat 1g of a substance by 1°C
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what colour is anhydrous copper (ii) sulfate powder
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white
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in what reaction do reactants have more energy than products
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exothermic reaction
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how do we know if a catalyst is effective in the decomposition of hydrogen peroxide
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if bubbles of oxygen gas are formed
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what is the position of equilibrium
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relative concentrations of reactants and products
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when is the reaction exothermic
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when the total energy released by making new bonds is higher than the total energy needed to break bonds
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what is room temp. (don't use kelvin)
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20°C
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what does the energy released by the forward direction equal
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energy absorbed by the backward direction
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if energy is released by the forward direction then what is the backwards direction
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energy is absorbed
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state the △H, increased temperature change, energy of products and reactants and the type of reaction of
CH₄ + H₂O ⇌ CO + 3H₂ |
it's an endothermic reaction because the forward direction is endothermic, we know this because our H₂O and CH₄ molecules are no where to be seen, so they must've been broken and bond breaking is endothermic so our reaction is endothermic. An endothermic reaction has a positive △H because reactants have less energy than products because reactants lose energy to the products meaning the △H is positive. If temperature is increased the position of equilibrium shifts to the right. This is because an increase in temperature means the surroundings get hotter, an endothermic reaction absorbs heat, this will counteract the warmth. balancing it out, restoring equilibrium. So we want to shift the position of equilibrium to the endothermic direction. This is the right, so position of equilibrium shifts to the right. So more product is made.
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9999999999999999999
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describe the table and graph of the reaction between sodium thiosulfate and hydrochloric acid when we vary the concentration of sodium thiosulfate
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the graph and table show that rate of reaction is directly proportional to concentration of sodium thiosulfate. This experiment can be repeated to show how temperature affects the rate of reaction, where we keep everything the same but just increase temperature.
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what can't a catalyst affect in a reversible reaction
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position of equilibrium
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what is water's c
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4.2 J/g °C
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what happens when the conditions of an equilibrium reaction change
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position of equilibrium changes to counteract the change in conditions in order to restore eqauilibrium
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describe and explain how to increase the rate of reaction with a gas without increasing temperature
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Increase the pressure of a gas, this means the same particles are present in a smaller volume which means there is less room for the gases to not react, so there are more particles per unit of volume as there is less volume for them to travel in. This makes more room for collisions so they will be more frequent which increases the rate of reaction.
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in what scenario can a dynamic equilibrium take place and why
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closed system so no substances can escape
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what is the activation energy
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minimum amount of energy a chemical reaction needs in order to take place
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how does the position of equilibrium change when there's an increase in pressure of this reaction:
CH₄ ₍₉₎ + H₂O₍₉₎ ⇌ CO₍₉₎ + 3H₂ ₍₉₎ |
first, see what side has more molecules of gas. 4 molecules on right and 2 molecules on left. So if pressure increases, position of equilibrium shifts to the left. This is because an increase in pressure means there is less space for molecules, so if we produce less particles we can decrease the pressure, this cancels out the increase in pressure so equilibrium is restored and more reactant is produced because it has less gas molecules.
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why do reactants have more energy than products sometimes
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reactants give heat energy to surroundings which warms the surroundings
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state the equation for △H
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△H = Q/mol
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if a reversible reaction is endothermic one way what will the other way be
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exothermic
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state the word equation between calcium carbonate and Hydrochloric acid in alphabetical order
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calcium carbonate + hydrochloric acid ─> calcium chloride + water + carbon dioxide
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what is the catalyst we use in the decomposition hydrogen peroxide
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manganese (IV) oxide (MnO₂)
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9999999999999999999
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state the chemical equation for the production of magnesium sulfate from magnesium
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Mg + CuSO₄ ̣̣─> MgSO₄ + Cu
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what is the difference in energy known as in a reaction profile
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△H
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describe and explain how to increase the rate of reaction with a solid without increasing temperature
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Increase the surface area of the solid, this makes the particles more exposed meaning they are distributed further throughout the solution. This results in more frequent collisions because there are more particles spread out. This increases the rate of reaction
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what colour is sodium thiosulfate solution
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colourless
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describe and explain how to increase the rate of reaction with a liquid without increasing temperature
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Increase the concentration of the liquid, this means more particles will be in the same volume, so there will be more particles per unit of volume, this produces more frequent collisions which increases the rate of reaction.
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99999999999999999
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how can a reaction be endothermic if the total energy released equals the total absorbed
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total energy needed to break all bonds is different for every compound
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can reactions have more gas molecules on one side
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yes
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what can concentration be measured in
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what is the molar enthalpy change
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enthalpy change per mole of a substance
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is forming bonds endothermic or exothermic
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exothermic
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do all bonds have a bond energy
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yes
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99999999999999999999
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describe how to carry out experiment between sodium thiosulfate and hydrochloric acid
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1: draw a large cross onto a piece of paper 2: place a conical flask onto the cross 3: pour sodium thiosulfate and hydrochloric acid into the beaker 4: observe the reaction directly above the flask 5: record the time taken for the cross to vanish 6: the cross vanishes because the yellow sulfur precipitate is formed |
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in an exothermic reaction, is △H negative or positive
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negative
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what colour are hydrated copper (ii) sulfate crystals
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blue
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what will happen if you carry out the calcium carbonate and hydrochloric acid experiment but with half the concentration of acid
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the volume and mass of acid stays the same it's just more diluted, otherwise the experiment would measure how much volume affects the rate of reaction. the marble chips need to be in excess, this reaction happens slower as they are less acid particles per unit of volume so the marble chip particles have to travel further to react so it takes longer. It produces exactly half the carbon dioxide as before and takes longer to reach the horizontal line which indicates the termination of the reaction.
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if forward direction is endothermic what is the backwards direction
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exothermic
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