In the following equation, which species is the oxidizing agent?
SiO2(s) + 2C(s) → Si(s) + 2CO(g)
SiO2
C
O
Si
C
You are performing an experiment that uses ^113Ag. ^113Ag is radioactive, decays by beta-minus emission and has a half-life of 5.3 hours. It requires 31.8 hours to ship the material from the warehouse to your laboratory. How many grams should you order if the experiment requires that you have 40 grams to begin the experiment?
We can use the radioactive decay equation to calculate the amount of ^113Ag that will be left after 31.8 hours of shipping and the initial amount of ^113Ag needed to end up with 40 grams after the decay:
N = N0 * e^(-λt)
where N is the final amount of ^113Ag, N0 is the initial amount, λ is the decay constant, and t is the time.
First, we can calculate λ:
λ = ln(2) / T
where T is the half-life. Plugging in the values:
λ = ln(2) / 5.3 = 0.1303 h^-1
Next, we can calculate the amount of ^113Ag that will be left after 31.8 hours of shipping:
N = N0 * e^(-λt) = 40 * e^(-0.1303 * 31.8) = 3.43 grams
Finally, we can calculate the initial amount of ^113Ag needed to end up with 40 grams after the decay:
N0 = N / e^(-λt) = 40 / e^(-0.1303 * 31.8) = 462.9 grams
Therefore, you should order 462.9 grams of ^113Ag to have 40 grams for your experiment after 31.8 hours of shipping and decay.
2.40 x 102 g
0.625 g
2.56 x 103 g
6.67 g
The answer is 462.9 grams.
What is the pressure exerted by 1.2 mol of a gas with a temperature of 20°C and a volume of 9.5 L?
3 atm
30 atm
0.030 atm
1 atm
We can use the ideal gas law to solve for the pressure:
PV = nRT
where P is the pressure, V is the volume, n is the number of moles, R is the gas constant, and T is the temperature in Kelvin.
To convert 20°C to Kelvin, we add 273.15:
T = 20°C + 273.15 = 293.15 K
Plugging in the values:
P = (nRT) / V = (1.2 mol * 0.0821 L atm/(mol K) * 293.15 K) / 9.5 L = 3.71 atm
Therefore, the pressure exerted by 1.2 mol of a gas with a temperature of 20°C and a volume of 9.5 L is approximately 3.71 atm. Answer: 3 atm.
The temperature is
how much force is exerted when the molecules hit the container wall.
how hot or cold an object is.
a measure of the average velocity of the molecules.
gas pressure above a liquid at equilibrium.
The temperature is:
how hot or cold an object is.
At 7.0°C, the volume of a gas is 49 mL. At the same pressure, its volume is 74 mL at what temperature?
150°C
3.0°C
120°C
423