Jim, because he ran a greater distance in the same time :)
By the way, this is a maths question
2.1648 kg of CH4 will generate 119341 KJ of energy.
Explanation:
Write down the values given in the question
CH4(g) +2 O2 → CO2(g) +2 H20 (g)
ΔH1 = - 802 kJ
2 H2O(g)→2 H2O(I)
ΔH2= -88 kJ
The overall chemical reaction is
CH4 (g)+2 O2(g)→CO2(g)+2 H2O (I) ΔH2= -890 kJ
CH4 +2 O2 → CO2 +2 H20
(1mol)+(2mol)→(1mol+2mol)
Methane (CH4) = 16 gm/mol
oxygen (O2) =32 gm/mol
Here 1 mol CH4 ang 2mol of O2 gives 1mol of CO2 and 2 mol of 2 H2O
which generate 882 KJ /mol
Therefore to produce 119341 KJ of energy
119341/882 = 135.3 mol
to produce 119341 KJ of energy, 135.3 mol of CH4 and 270.6 mol of O2 will require
=135.3 *16
=2164.8 gm
=2.1648 kg of CH4
2.1648 kg of CH4 will generate 119341 KJ of energy
Answer: -
The approximate number of atoms in a bacterium is 10¹¹
Explanation: -
We are given the mass of a bacterium is 10⁻¹⁵ kg.
We are told that the mass of a hydrogen atom is 10⁻²⁷ kg.
Finally we learn that the average mass of an atom of the bacterium is ten times the mass of a hydrogen atom.
Mass of an atom of bacterium = 10 x mass of hydrogen atom
= 10 x 10⁻²⁷ kg.
= 10⁻²⁶ kg.
Thus the number of atoms in a bacterium = 
= 
= 10¹¹
Answer:
Explanation:
Here, we want to calculate the number of formula units in the given molecule
We start by getting the number of moles
To get the number of moles, we have to divide the mass given by the molar mass
The molar mass is the mass per mole
The molar mass of calcium bromide is 200 g/mol
Thus, we have the number of moles as follows:
The number of formula units in a mole is:
The number of formula units in 0.2075 mole will be:
Answer:
Considering the half-life of 10,000 years, after 20,000 years we will have a fourth of the remaining amount.
Explanation:
The half-time is the time a radioisotope takes to decay and lose half of its mass. Therefore, we can make the following scheme to know the amount remaining after a period of time:
Time_________________ Amount
t=0_____________________x
t=10,000 years____________x/2
t=20,000 years___________x/4
During the first 10,000 years the radioisotope lost half of its mass. After 10,000 years more (which means 2 half-lives), the remaining amount also lost half of its mass. Therefore, after 20,000 years, the we will have a fourth of the initial amount.
