What are the answer choices?
Answer:
After 1326s, the concentration of pyruvic acid fall to 1/64 of its initial concentration.
Explanation:
The first order kinetics reaction is:
ln [A] = ln [A]₀ - kt
<em>Where [A] is concentration after t time, [A]₀ is intial concentration and k is reaction constant.</em>
To convert half-life to k you must use:
t(1/2) = ln 2 / K
221s = ln 2 / K
K = ln 2 / 221s
<h3>K = 3.1364x10⁻³s⁻¹</h3>
If [A] = 1/64, [A]₀ = 1:
ln [A] = ln [A]₀ - kt
ln (1/64) = ln 1 - 3.1364x10⁻³t
4.1588 = 3.1364x10⁻³s⁻¹t
1326s = t
<h3>After 1326s, the concentration of pyruvic acid fall to 1/64 of its initial concentration.</h3>
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D. A disadvantage of nuclear power is that waste products are unsafe and hard to store. They must be stored for many hundreds of years before they becomes safe and easier to dispose of, and we currently don't have a good method of storing them in the meantime.
The molar mass of the gas is 77.20 gm/mole.
Explanation:
The data given is:
P = 3.29 atm, V= 4.60 L T= 375 K mass of the gas = 37.96 grams
Using the ideal Gas Law will give the number of moles of the gas. The formula is
PV= nRT (where R = Universal Gas Constant 0.08206 L.atm/ K mole
Also number of moles is not given so applying the formula
n= mass ÷ molar mass of one mole of the gas.
n = m ÷ x ( x molar mass) ( m mass given)
Now putting the values in Ideal Gas Law equation
PV = m ÷ x RT
3.29 × 4.60 = 37.96/x × 0.08206 × 375
15.134 = 1168.1241 ÷ x
15.134x = 1168.1241
x = 1168.1241 ÷ 15.13
x = 77.20 gm/mol
If all the units in the formula are put will get cancel only grams/mole will be there. Molecular weight is given by gm/mole.
Answer:
7.12 mm
Explanation:
From coulomb's law,
F = kqq'/r².................... Equation 1
Where F = force, k = proportionality constant, q and q' = The two point charges, r = distance between the two charges.
Make r the subject of the equation,
r = √(kqq'/F).......................... Equation 2
Given: q = q' = 75.0 nC = 75×10⁻⁹ C, F = 1.00 N
Constant: k = 9.0×10⁹ Nm²/C².
Substitute into equation 2
r = √[ (75×10⁻⁹ )²9.0×10⁹/1]
r = 75×10⁻⁹.√(9.0×10⁹)
r = (75×10⁻⁹)(9.49×10⁴)
r = 711.75×10⁻⁵
r = 7.12×10⁻³ m
r = 7.12 mm
Hence the distance between the point charge = 7.12 mm