Answer: The millimoles of sodium carbonate the chemist has added to the flask are 256
Explanation:
Molarity is defined as the number of moles dissolved per liter of the solution.
To calculate the number of moles for given molarity, we use the equation:
.....(1)
Molarity of 
solution = 1.42 M
Volume of solution = 180.0 mL
Putting values in equation 1, we get:
Thus the millimoles of sodium carbonate the chemist has added to the flask are 256.
Answer:
Rank the following chemical species from lowest absolute entropy (So) (1) to highest absolute entropy (5) at 298 K?
a. Al (s)
b. H2O (l)
c. HCN (g)
d. CH3COOH (l)
e. C2H6 (g)
Explanation:
Entropy is the measure of the degree of disorderness.
In solids, the entropy is very less compared to liquids and gases.
The entropy order is:
solids<liquids<gases
Among the given substances, water in liquid form has a strong intermolecular H-bond.
So, it has also less entropy.
Next acetic acid.
Between the gases, HCN, and ethane, ethane has more entropy due to very weak intermolecular interactions.
HCN has slight H-bonding in IT.
Hence, the entropy order is:
Al(s) < CH3COOH (l) <H2O(l) < HCN(g) < C2H6(g)
Answer:
is the approximate energy of one photon of this light.
Explanation:
Energy of the photon can be calculated by
(Planck's equation)
where,
E = energy of photon
h = Planck's constant = 
c = speed of light = 
= wavelength of light =
= frequency of the light
we have , 
Now put all the given values in the above formula, we get the energy of the photons.
is the approximate energy of one photon of this light.
An acidic solution is 0.1M in HCl and 0.2 H2so4. volume is equal to no of moles divided by molarity.
number of moles of HCl is 450ml x 0.1 divided by 1000 which is equal to 0.045 moles
volume of HCl is therefore 0.45 divided by 0.16 which is 2.81 litres
Number of moles of H2so4 is 450ml x 0.2 divided by 1000 which is equal to 0.09 moles
volume of H2SO4 IS 0.09 divided by 0.16 which is equal to 0.56 litres
