Answer:
Adding heat and increasing concentration are meant to cause an increase in the rate of a reaction
Explanation:
The rate of a chemical reaction is defined as the number of moles of reactants converted or products formed pee unit time. It is a measure of how quickly the reactants in a given reaction are used up to form products or how quickly products are formed from reactants.
Factors that affect the rate of a chemical reaction include:
1. Nature of reactants
2. Concentration/pressure (for gases) of reactants
3. Temperature of reaction mixture
4. Presence of light
5. Presence of a catalyst
The effect of increasing the concentration of reactants for a given chemical reaction is that the reaction rate will increase. This is so because, according to the collision theory of chemical reactions, the frequency of collision between reactant particles which results in a chemical reaction (effective collisions) will increase when the reactant particles are crowded together in a small space due to an increase in their concentration.
The effect of increasing temperature or adding heat to a reaction is that the reaction rate increases. When the heat is added to a reactant particles, the number of particles with energies greater than or equal to the activation energy (the minimum amount of energy that reactant particles must possess for effective collisions) increases. Also, the average speed of the reactant particles increases resulting in a greater frequency of collision. Hence, the rate of the chemical reaction increases.
False. Eyeglasses do not cover all around the eye however safety goggles do
Answer:
You should start with 63.54 grams of copper.
Explanation:
The chemical reactions are processes in which the nature of the substances changes, that is, from some initial substances called reactants, totally different ones called products are obtained.
In the chemical reaction, the formulas of reagents and products appear preceded by numbers (the stoichiometric coefficients) that indicate the proportions according to which the transformation occurs. So you can say that stoichiometry establishes relationships between the molecules or elements that make up the reactants of a chemical equation with the products of said reaction. The relationships that are established are MOLAR relationships between the compounds or elements that make up the chemical equation: always in MOLES.
The stoichiometric coefficients of a chemical equation are due to the fact that the atoms present before the reaction must be the same after the reaction, although they will have been rearranged to produce new substances.
If you want 2 moles of silver (Ag), for stoichiometry of the reaction you need a moles of copper Cu. Being the molar mass of copper Cu 63.54 g / mole, then:
1 mole*63.54 g/mole= 63.54 g
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To determine the standard heat of reaction, ΔHrxn°, let's apply the Hess' Law.
ΔHrxn° = ∑(ν×ΔHf° of products) - ∑(ν×ΔHf° of reactants)
where
ν si the stoichiometric coefficient of the substances in the reaction
ΔHf° is the standard heat of formation
The ΔHf° for the substances are the following:
CH₃OH(l) = -238.4 kJ/mol
CH₄(g) = -74.7 kJ/mol
O₂(g) = 0 kJ/mol
ΔHrxn° = (1 mol×-74.7 kJ/mol) - ∑(1 mol×-238.4 kJ/mol)
ΔHrxn° = +163.7 kJ
O valence electron number is the answer
