Answer:
9,500J
Explanation:
Distance= 50m
Force = 190N
Energy = Force x distance
= 190 x 50
= 9,500J
The temperature change is 96.9 °C
Using Q = mcΔT where Q = quantity of energy applied = 250 J, m = mass of gold = 20 g, c = specific heat capacity of gold = 0.129 J/g °C and ΔT = temperature change
Since we require the temperature change, making ΔT subject of the formula, we have
ΔT = Q/mc
substituting the values of the variables into the equation, we have
ΔT = 250 J/(20 g × 0.129 J/g °C)
ΔT = 250 J/(2.58 J/°C)
ΔT = 96.89 °C
ΔT ≅ 96.9 °C
So, the temperature change is 96.9 °C
Learn more about temperature change here:
brainly.com/question/16384350
8. A - they’re repeating the action
9. B -Frank, himself hasn’t done the experiment before
Answer:
Explanation:
Oxygen is one of the most abundant elements on this planet. Our atmosphere is 21% free elemental oxygen. Oxygen is also extensively combined in compounds in the earths crust, such as water (89%) and in mineral oxides. Even the human body is 65% oxygen by mass.
Free elemental oxygen occurs naturally as a gas in the form of diatomic molecules, O2 (g). Oxygen exhibits many unique physical and chemical properties. For example, oxygen is a colorless and odorless gas, with a density greater than that of air, and a very low solubility in water. In fact, the latter two properties greatly facilitate the collection of oxygen in this lab. Among the unique chemical properties of oxygen are its ability to support respiration in plants and animals, and its ability to support combustion.
In this lab, oxygen will be generated as a product of the decomposition of hydrogen peroxide. A catalyst is used to speed up the rate of the decomposition reaction, which would otherwise be too slow to use as a source of oxygen. The catalyst does not get consumed by the reaction, and can be collected for re-use once the reaction is complete. The particular catalyst used in this lab is manganese(IV) oxide.
Answer:
increases the frequency of particle collisions
Explanation:
One factor upon which the rate of reaction depends is the surface area of reactants.
According to the collision theory, reactions occur when reactant particles having the required (activation) energy collide with each other, this collision is inelastic. However, collision of particles having energies less than the activation energy results in elastic collisions and no chemical reaction.
The more the exposed surface area of reactants, the greater the number of particles that come into contact with each other and the more the chances of frequent effective collisions that lead to reaction.
Thus, powdered zinc reacts faster with hydrochloric acid than zinc strips