The correct answer is option A. Energy cannot be created during an ordinary chemical reaction. There is no such thing as an ordinary chemical reaction. Energy cannot be created or destroyed this is according to the law of conservation of energy. It can only be transformed from one form to another form.
Answer:
Explanation:
Use the gas equation: PV=nRT
P=pressure
V=Volume
R= gas constant of around 8.31 J/K/mol
T=temperature
n= number of moles
To find n, Rearrange:
n=PV/RT
102kPa= 102,000 kilo pascals which standard form is 102 x 10^3
Convert Celsius to kelvin, which you just add 273.15. So:
37+273.15=310.15 K round to a whole number is 310 K
Sub in all numbers to calculate the mol
n= 102 x 10^3 x 2.20 x 10^3/ 8.31 x 310 (cross out 10^3 as this will make a big number)
n=102 x 2.2/8.31 x 310 =0.087 mol
We know 1 g=29 moles
Multiply 29 moles with 0.087 to find the grams
29*0.087=2.523, which to one d.p is 2.5 g
Hence, the child's lung will hold 2.5 g of air.
Hope this helps you :)
Have a nice day!!
Answer is: 5,9.
Effusion is leakage of gas
through a small hole. Gases with a lower molecular mass effuse more speedy than gases with a higher molecular mass. R<span>elative rates of effusion is related to the molecular mass.
</span>M(O₂) = 32g/mol.
M(CO₂) = 44g/mol.
t₁ = 5s.
t₂ = ?
t₂/t₁ = √(M(CO₂)/M(O₂)).
t₂ = 1,17·5s = 5,9s.
Nylon 6,6 is a common example of a polyamide.
<em>Polyamides</em> are polymers that contain <em>repeating amide (-CO-NH-) linkages</em>.
The structure of Nylon 6,6 is
[-NH-(CH_2)_6-<u>NH-CO</u>-(CH_2)_4-CO-]_<em>n</em>
where <em>n</em> is a large number.
The numbers in the name showow that there are six carbon atoms on either side of an amide linkage.
Answer is: 550,021 kWh of energy is needed to heat the water
V(water) = 51 gal = 51·3,78 = 189,3 L.
ΔT(water) = 25°C.
d(water) = 1000 g/L.
m(water) = V(water) · d(water)
m(water) = 189,3 L · 1000 g/L
m(water) = 189300 g.
Q = m(water) · ΔT(water) · C(water)
Q = 189300 g · 25°C · 4,184 J/°C·g
Q = 19800780 J = 19800,78 kJ ÷ 3600 = 550,021 kWh.
