Brass is an alloy, or a combination of two (or more) metals.
B. Troposphere, stratosphere, mesosphere, thermosphere
The rate of a chemical reaction is affected by temperature, Catalysts, Suface area, Concentration.
<h3>Rate of reaction</h3>
The rate of a chemical reaction is the rate at which the concentration of reactant molecules decreases or the concentration of product molecules increases.
<h3>Factors effecting rate of chemical reaction </h3>
The factors that affect the rate of chemical reaction include:
- Temperature: increase in temperature increases reaction rate while decrease in temperature decreases reaction rate.
- Catalysts: the present of catalysts increase the reaction rate. Some catalysts decreases reaction rate and are known as negative catalysts.
- Surface area: increase in surface area of reactants increases reaction rate.
- Concentration: Increase in concentration of reactants increases reaction rate while decrease in concentration of reactants decreases reaction rate.
Therefore, the rate of a chemical reaction is affected by temperature, Catalysts, Suface area, Concentration.
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Answer:
97.1%
Explanation:
Using the ideal gas equation, the number of moles of hydrogen gas produced can be calculated from information provided about the volume of gas evolved at a given temperature and pressure.
The stoichiometry of the reaction is now used to obtain the number of moles of Zn that will produce a given number of moles of hydrogen from the balanced reaction equation as shown. This gives us the number of moles of zinc reacted hence the mass of zinc in the coin since it is assumed that all the zinc reacts.
This is now used to calculate the mass percentage of Zn as shown.