<u>Answer:</u> The correct answer is Option A.
<u>Explanation:</u>
Standard enthalpy of formation is the change in enthalpy of one mole of a substance present at the standard state that is 1 atm of pressure and 298 K of temperature. The substance is formed from its pure elements under the same conditions.
We are given a chemical compound having chemical formula 
This compound is formed by the combination of calcium, nitrogen and oxygen elements.
The chemical equation for the formation of from the components in their standard states follows:
Hence, the correct answer is Option A.
Answer:
-10778.95 J heat must be removed in order to form the ice at 15 °C.
Explanation:
Given data:
mass of steam = 25 g
Initial temperature = 118 °C
Final temperature = 15 °C
Heat released = ?
Solution:
Formula:
q = m . c . ΔT
we know that specific heat of water is 4.186 J/g.°C
ΔT = final temperature - initial temperature
ΔT = 15 °C - 118 °C
ΔT = -103 °C
now we will put the values in formula
q = m . c . ΔT
q = 25 g × 4.186 J/g.°C × -103 °C
q = -10778.95 J
so, -10778.95 J heat must be removed in order to form the ice at 15 °C.
Answer:
Explanation:
The relation between new scale and absolute temperature scale is given as follows
Aw = 2 K
for K = 273.15 ( freezing point of water at absolute scale )
Aw = 2 x 273.15 = 546.3 K
So each division of new scale is half the each division of absolute scale
each division of new scale is small .
The value of R = 8.314 J per mole per K
Here per K is equivalent to 2Aw
So the vale of R in new scale = 8.314/2 J per mole per Aw
= 4.157 J per mole per Aw
k = R / N
= 4.157 / 6.02 x 10²³
= .69 x 10⁻²³
= 6.9 x 10⁻²⁴ J per molecule per Aw .
Answer:
( About ) 0.03232 M
Explanation:
Based on the units for this reaction it should be a second order reaction, and hence you would apply the integrated rate law equation "1 / [X] = kt + 1 / [
]"
This formula would be true for the following information -
{ = the initial concentration of X, k = rate constant, [ X ] = the concentration after a certain time ( which is what you need to determine ), and t = time in minutes }
________
Therefore, all we have left to do is plug in the known values. The initial concentration of X is 0.467 at a time of 0 minutes, as you can tell from the given data. This is not relevant to the time needed in the formula, as we need to calculate the concentration of X after 18 minutes ( time = 18 minutes ). And of course k, the rate constant = 1.6
1 / [X] = ( 1.6 )( 18 minutes ) + 1 / ( 0.467 ) - Now let's solve for X
1 / [X] = 28.8 + 1 / ( 0.467 ),
1 / [X] = 28.8 + 2.1413...,
1 / [X] = 31,
[X] = 1 / 31 = ( About ) 0.03232 M
Now for this last bit here you probably are wondering why 1 / 31 is not 0.03232, rather 0.032258... Well, I did approximate one of the numbers along the way ( 2.1413... ) and took the precise value into account on my own and solved a bit more accurately. So that is your solution! The concentration of X after 18 minutes is about 0.03232 M
Answer:
47.5 mm are equal to 4.75 × 10⁻² m.
Explanation:
Meter and millimeter both are units of length. Millimeter is smaller unit while meter is larger unit. The one meter consist of thousand millimeter or we can say that one thousand millimeters are equal to one meter. In order to convert the meter value into millimeter we have to multiply the values with thousand.
we know that one meter is equal to 1000 millimeter.
1 m = 1000 mm
4.75 × 10⁻² × 1000 = 47.5 mm
47.5 mm are equal to 4.75 × 10⁻² m.
