Answer:
200 W
Explanation:
Formula of Power is
P= W/T
where
W= Work and T= Time
so
4000/20 = 200J/s or 200 W
Answer:
The most effective buffer at pH 9.25 will be a mixture of 1.0 M NH3 and 1.0 M NH4Cl
Explanation:
Step 1: Data given
pH of a buffer = pKa + log ([A-]/[Ha])
a mixture of 1.0 M HC2H3O2 and 1.0 M NaC2H3O2 (Ka for acetic acid = 1.8 x 10-5)
pH = -log( 1.8 * 10^-5) + log (1/1)
pH = -log( 1.8 * 10^-5)
pH = 4.74
a mixture of 1.0 M NaCN and 1.0 M KCN (Ka for HCN = 4.9 x 10-10)
pH = -log( 4.9 * 10^-10) + log (1/1)
pH = -log( 1.8 * 10^-5)
pH = 9.30
a mixture of 1.0 M HCl and 1.0 M NaCl
The solution made from NaCl and HCl will NOT act as a buffer.
HCl is a strong acid while NaCl is salt of strong acid and strong base which do not from buffer solutions hence due to HCl PH is less than 7.
a mixture of 1.0 M NH3 and 1.0 M NH4Cl (Kb for ammonia = 1.76 x 10^-5)
Ka * Kb = 1*10^-14
Ka = 10^-14 / 1.76*10^-5
Ka = 5.68*10^-10
pH = -log( 5.68*10^-10) + log (1/1)
pH = -log( 5.68*10^-10)
pH = 9.25
The most effective buffer at pH 9.25 will be a mixture of 1.0 M NH3 and 1.0 M NH4Cl
5. The difference between mass and weight it that mass is the volume inside a object.
Transition metals are less reactive than alkali metals because of their high ionization potential and high melting point.
On moving from left to right of the periodic table for every period, electrons fill in the same shell or orbital, with the alkali metals having the least filled outermost shells, one electron, which equates to fewer protons in them.
Consequently, they have a lesser attraction power from the nucleus, whereas, the corresponding transition metals of the same period have more protons interacting with electrons at the same distance, far from the nucleus as the alkali metals.
Answer:
what are the following statements?
Explanation:
