Answer:
a) pH will be 12.398
b) pH will be 4.82.
Explanation:
a) The moles of NaOH added = molarity X volume (L) = 2 X 0.01 = 0.02 moles
The total volume after addition of pure water = 0.780+0.01 = 0.79 L
The new concentration of /NaOH will be:
the [OH⁻] = 0.025
pOH = -log [OH⁻] = 1.602
pH = 14 -pOH = 12.398
b) The buffer has butanoic acid and butanoate ion.
i) Before addition of NaOH the pH will be calculated using Henderson Hassalbalch's equation:
![pH=pKa+log\frac{[salt]}{[acid]}](https://tex.z-dn.net/?f=pH%3DpKa%2Blog%5Cfrac%7B%5Bsalt%5D%7D%7B%5Bacid%5D%7D)
pKa=
ii) on addition of base the pH will increase.
<span>There are a number of ways
to express concentration of a solution. This includes molarity. Molarity is
expressed as the number of moles of solute per volume of the solution.
Calculations are as follows:
Molarity of NO3 ion = 32.0 g Mg(NO3)2 ( 1 mol / 148.3 g ) ( 2 mol NO3 / 1 mol Mg(NO3)2) / .425 L
MOlarity of NO3 ion = 1.02 M </span><span>
</span>
Answer:
The element with electronic configuartion 1s² and atomic number 3 must be an cation.
Explanation:
The "Z" shows the atomic number. Z stand for zahl. It Is German word and meaning is " number".
In given question Z is equal to three which means an element with atomic number three.
Let consider the X is an element with atomic number three having electronic configuration 1s², but according to this atomic number there should be one more electron present is 2s. If X has the electronic configuration 1s² it means that it lose one electron and X is present in the form of cation.
X⁺ = 1s²
Answer:
75 Newton
Explanation:
In order to find the force of the object, you must remember that the equation N = (mass x acceleration). Therefore meaning you would divide 300 kilograms, <em>the mass, </em>by 4 meters per second (squared), <em>the acceleration.</em>
Answer:
- 618.8 J.
Explanation:
- To solve this problem, we can use the relation:
<em>Q = m.c.ΔT,</em>
where, Q is the amount of heat released by steam (Q = ??? J).
m is the mass of the steam (m = 15.5 g).
c is the specific heat of the steam (c of steam = 1.996 J/g.°C).
ΔT is the difference between the initial and final temperature (ΔT = final T - initial T = 100.0°C - 120.0°C = - 20.0°C).
<em>∴ Q = m.c.ΔT</em> = (15.5 g)(1.996 J/g.°C)(- 20.0°C) =<em> - 618.8 J.</em>
