Answer:
1.5057×10^22 atom
Explanation:
As we
1 mole of argon = 40 g of argon
i.e 40 g of argon = 1 mole of argon
1 g of argon = 1/40 mole of argon
1 mole of argon = 6.023×10^23 atom of argon
1/40 mole if argon = 1/40 ×6.023×10^23
= 1.5057×10^22
Answer:
Explanation:
<u>1) Find the z-scores:</u>
a) z-score for 22.6 inches length
- z = [ 22.6 - 20 ] / 2.6 = 1.00
b) z-score for 17.4 inches length
- z = [ 17.4 - 20 ] / 2.6 = - 1.00
<u>2) Probability</u>
Then, you have to find the probability that the length of an infant is between - 1.00 and 1.00 standards deviations (σ) from the mean (μ).
That is a well known value of 68%, which is part of the 68-95-99.7 empirical rule.
The most exact result is obtained from tables and is 68.26%:
- 1 - P (z ≥ 1.00) - P (z ≤ - 1.00) = 1 - 0.1587 - 0.1587 = 0.6826 = 68.26%
Activation energy is the minimum amount of energy that the colliding reactant molecules must possess for the formation of products. Lower the activation energy, higher will be chance of formation of products. So activation energy is the minimum energy requirement that has to overcome for the reaction to be completed. Therefore, when in a chemical reaction the reactant molecules do not collide with required activation energy, the collisions will not be fruitful even if they are properly oriented which means that the products will not form.
Hence the correct answer will be B.) no products will be formed
Answer:
Explanation:
For the reaction
C2H5OH (l) + 3 O2(g) = 2CO2(g) + 3 H2O
We can calculate the standard molar enthalpy of combustion using the standard enthalpies of formation of the species involved in the reaction according to Hess law:
ΔHºc = 2ΔHºf CO2 (g) + 3ΔHºfH2O(l) - ( ΔHºf C2H5OH (l) - 3ΔHºfO2 (g) )
( we were not give the water state but we know we are at standard conditions so it is in its liquid state )
The ΔHºfs can be found in appropiate reference or texts.
ΔHºc = 2ΔHºf CO2 (g)+ 3ΔHºfH2O(l) - ( ΔHºf C2H5OH (l) -+3ΔHºfO2 (g) )
= [ 2 ( -393.52 ) + 3 ( -285.83 ) ] - [( -276.2 + 0 ) ] kJ
ΔHºc = -1368.33 kJ
