The SI unit of temperature is the kelvin (K), which spans the same temperature change as the degree Celsius. The Kelvin scale is a thermodynamic scale, meaning that its zero point is at absolute zero rather than the freezing point of water. The second reference point for this scale as it is currently defined is the triple point of water, which is a unique point on the phase diagram of water (a specific combination of pressure and temperature) where ice, liquid water and water vapor are all in equilibrium. The triple point is assigned the temperature of 273.16 K.
The old centigrade scale used the freezing and boiling temperatures of water as its reference points, with one degree centigrade equal to 1/100 of the temperature span between the freezing and boiling points of water. The definition of the Kelvin scale was chosen to make the kelvin the same size as the centigrade degree.
The Celsius scale is defined in terms of the Kelvin scale but is equivalent to the old centigrade scale, which it replaces. It is convenient for reporting weather and cooking temperatures and so on, but is not particularly useful for scientific purposes. For instance, the behavior of gases which approximate ideal gases is such that at zero degrees C they experience a volume change of 1/273 for a one degree change in temperature. This observation provided one of the first indications for the value of absolute zero.
When using the ideal gas law:
PV = nRT
where P is pressure
V is volume
n is the quantity of gas in moles
R is a constant
T is the temperature
it is necessary to use a thermodynamic scale, usually Kelvin.
Another thermodynamic scale, the Rankine scale, has a relationship to the Fahrenheit temperature scale analogous to that between the Kelvin and Celsius scales.
Answer:
Subatomic particles making up an atom
Explanation:
Atom is the smallest unit of any matter
An atom consists of three subatomic particles - Protons, Neutrons, Electrons. Major atomic mass is in the nucleus ie a tiny deep area at the centre. Nucleus consists nucleons, which includes protons (positively charge) & neurons (neutrally charged). Negatively charged electrons are outside the central nucleus.
Answer:
25.907°C
Explanation:
In Exercise 102, heat capacity of bomb calorimeter is 6.660 kJ/°C
The heat of combustion of benzoic acid is equivalent to the total heat energy released to the bomb calorimeter and water in the calorimeter.
Thus:
= heat of combustion of benzoic acid
= heat energy released to water
= heat energy released to the calorimeter
Therefore,
1.056*26.42 = [0.987*4.18 + 6.66]( - 23.32)
27.8995 = [4.12566+6.660]( - 23.32)
( - 23.32) = 27.8995/10.7857 = 2.587
= 23.32 + 2.587 = 25.907°C
Answer:
Curators
Explanation:
Definition from the dictionary
The complete balanced chemical reaction for this would be:
<span>NaOH + C3H6O3
--> NaC3H5O3 + H2O</span>
So we see that exactly 1 mole of NaOH reacts with 1 mole
of lactic acid.
Calculate moles of NaOH.
moles NaOH = 0.07 moles/L * 0.0268 L
moles NaOH = 1.876 x 10^-3 mol
So,
moles C3H6O3 = 1.876 x 10^-3 mol
The molar mass of lactic acid is 90.08 g/mol so the mass
is:
mass C3H6O3 = (1.876 x 10^-3 mol) * 90.08 g/mol
<span>mass C3H6O3 = 0.169 g</span>