Answer:
(c) pH = -log [H^+]
Explanation:
pH defines the acidicity or basicity a solution.
pH also refers to hydrogen ion concentration and it is only applied to aqueous solution.
pH ranges from 0 to 14. A pH of 7 is neutral and a pH less than 7 is acidic while a pH higher than basic.
Answer: A. Exothermic reaction
Explanation: Enthalpy change for a reaction is sum of enthalpy of formation of products minus sum of enthalpy of formation of reactants.
When the energy level of reactants is above as compared to the products, the reaction is exothermic and when its opposite then reaction is endothermic.
From given information, the potential energy diagram starts at 380 kJ means the energy level of reactants is 380 kJ. It ends at 100 kJ means the energy of products is 100 kJ.
Enthalpy of reaction = 100 kJ - 380 kJ
Enthalpy of reaction = -280 kJ
Negative sign of enthalpy change indicates an Exothermic reaction.
Answer:
An increase in entropy
Explanation:
In ice, the molecules are very well ordered because of the H-bonds. As ice melts, the intermolecular forces are broken (requires energy), but the order is interrupted (so entropy increases). Water is more random than ice, so ice spontaneously melts at room temperature.
Just think about this rationally. Melting ice (or anything) will require heat put in (this is called the latent heat of fusion), so you automatically know that the change in enthalpy is going to be positive. In order to make the reaction spontaneous, delta G, the Gibbs free energy has to be negative. So now look at the formula Delta(G) = Delta(H) - T*Delta*(S). If you know that g is negative, and H is positive, then it is only possible if -T*Delta(S) is negative. If that is positive, then Delta(S) has to be positive. So theres your answer :). An increase in entropy
C.Pennsylvania Titusville is in the state of Pennsylvania
answer: its 7290 joules.
explanations: the first procedure is to convert 1 pound to kilogram. 1 kg = 2.205 hence given 100 lb so we cross multiply. 1 kg * 100 = 2.205 * x
hence x= 45 kg. let's convert 1 mile per hour = 0.45 metre per second we cross multiply by 40 mile per hour. x= 40 * 0.45= 18 m/s.
KE= 1/2 * 45 * (18)^2
= 1/2 * 45 * 14580
= 7290joules
