1. Answer;
=56 g/mol
Explanation and solution;
PV = nRT
nRT= mass/molar mass (RT)
molar mass = (mass/V ) × (RT/P)
= Density × (RT/P)
Molar mass = 2.0 g/L × (0.0821 × 323 K)/0.948 atm
Molar mass = 56 g/mol
2. Answer;
Molecular mass is C4H8
Explanation;
Empirical mass × n = molar mass
Empirical mass for CH2 = 14 g/mol
Therefore;
56 g/mol = 14 g/mol × n
n = 4
The molecular formula= 4(CH2)
= C4H8
Answer:
The correct answer is
B.
Explanation:
Enthalpy of reaction :
It is the amount of energy released/absorbed when one mole of the substance is formed from the reactant at a constant pressure.
The enthalpy of a reaction can be calculated using :
Please note that :
The carbon monoxide , CO should be taken as C triple bond O. Not C=O .
So , the bond energy =1072 is used
D
A- Harvard university professor
Answer: A sea of electrons
Explanation:
Answer:
Check the explanation
Explanation:
AT = A0 e(-T/H)
... where A0 is the starting activity, AT is the activity at some time T, and H is the half-life, in units of T.
Substituting what we know, we get...
0.71 = (1) e(-T/5730)
Solve for T...
loge(0.71) = -T/5730
T = -loge(0.71)(5730)
T = 1962 (conservatively rounded, T = 2000)
similarly for all
for aboriginal charcoal
0.28 = (1) e(-T/5730)
Solve for T...
loge(0.28) = -T/5730
T = -loge(0.28)(5730)
T = 7294 (conservatively rounded, T = 7000)
for mayan headdress
0.89 = (1) e(-T/5730)
Solve for T...
loge(0.89) = -T/5730
T = -loge(0.89)(5730)
T = 667 (conservatively rounded, T = 700)
for neanderthal
0.05 = (1) e(-T/5730)
Solve for T...
loge(0.05) = -T/5730
T = -loge(0.05)(5730)
T = 17165 (conservatively rounded, T = 17000)
