In general terms, exothermic reactions release energy, so the energy goes from the system to the surroundings.
Answer:
It is not water absorbant and also the colour black, due to it's dark nature makes the person wearing the cloth feel hot. Unlike cotton, silk is not at all water absorbant as it does not absord any sweat produced in the wearers body
The given reaction is:
C4H10 + O2 → CO2 + H2O
The above equation is not balanced due to the unequal distribution of atoms on either side of equation
# atoms Reactants # atoms products
C = 4 C = 1
H = 10 H = 2
O = 2 O = 3
In order to balance it, multiply C4H10 by 2, O2 by 13, CO2 by 8 and H2O by 10 to get:
2C4H10 + 13 O2 → 8CO2 + 10H2O
Answer:
Choice A: Approximately
joules.
Explanation:
Apply the famous mass-energy equivalence equation to find the energy that correspond to the
kilograms of mass.
,
where
stands for energy,
stands for mass, and
is the speed of light in vacuum.
The speed of light in vacuum is a constant. However, finding the right units for this value can simplify the calculations a lot. What should be the unit of
?
The mass given is in the appropriate SI unit:
Mass is in kilograms.
Thus, proceed with the speed of light in SI units. The SI unit for speed is meters per second. For the speed of light,
.
Apply the mass-energy equivalence:
.
The unit of energy is not in joules. Don't be alerted. Consider the definition of a joule of energy. One joule is the work done on an object when a force of one newton acts on the object in the direction of the force through the distance of one meter. (English Wikipedia.)
.
However, a force of one newton is defined as the force required to accelerated an object with a mass of one kilogram (not gram) at a rate of one meter per second squared. (English Wikipedia.)
.
In other words, the mass defect here is also
.