Answer:
180 mg
Explanation:
For a first-order reaction, we can calculate the amount of aspirine (A) at a certain time (t) using the following expression.

where,
k: rate constant
A₀: initial amount
If we know the half-life (
) we can calculate the rate constant.

When t = 4 h and A₀ = 400 mg, A is:

All particles (atoms and molecules) of matter have kinetic energy because they are always in motion.
A measure of the kinetic energy of particle motion within a substance is temperature. If the particles move faster, they have more kinetic energy, and the substance has a higher temperature
Answer:
CaCl2, Li2S, AlCl3, AlCl3, K2S
Explanation:
When figuring out which is a better conductor of electricity you want to look at which has the largest yield of dissociated ions.
Answer: Velocity
Explanation:
i just took the quiz for k12
Answer:
True => ΔH°f for C₆H₆ = 49 Kj/mole
Explanation:
See Thermodynamic Properties Table in appendix of most college level general chemistry texts. The values shown are for the standard heat of formation of substances at 25°C. The Standard Heat of Formation of a substance - by definition - is the amount of heat energy gained or lost on formation of the substance from its basic elements in their standard state. C₆H₆(l) is formed from Carbon and Hydrogen in their basic standard states. All elements in their basic standard states have ΔH°f values equal to zero Kj/mole.