A buffer is usually composed of either:
- a weak base combined with its conjugate acid, or
- a weak acid combined with its conjugate base
Now, examining each of the choices:
1- KOH and NH3: since they are both bases, thus this mixture is not a buffer
2- HBr and NaCl: since HBr is a strong acid while NaCl is the salt of another different acid, thus this mixture is not a buffer
3- HCl and HBr: these are both considered to be strong acid, thus this mixture is not a buffer
4- HCHO2 and NaCHO2: as for HCH02, it is considered a weak base while NaCHO2 is considered its conjugate base, thus this mixture is a buffer
Answer:
2) HClO3 is stronger because chlorine is more electronegative than iodine.
Explanation:
The more electronegative the element is the more strong or acidic it becomes.
Chlorine being more electronegative than Iodine makes it easier for it to pull the electron of hydrogen more strongly and hence has a higher tendency to release a H+ unit. Hence that makes it stronger.
Answer: The electron configuration of carbon atom is written as 1s²,2s², 2p².
Explanation:
The electronic configuration of an atom is defined as the arrangement of electrons into the shells or orbit of an atom. The constituents of an atom are proton, neutron and electron. the nucleus of an atom, where most of its mass are concentrated, consists of neutrons and protons fused together. Electrons occupy the shells surrounding the nucleus. The shells are lettered K, L, M, N and so on. Numerically, K shell is numbered 1, L is 2 and so on. These numbers also correspond with the increase in the energy level. All the electrons in K shell for instance belong to the first energy level and they have equal energy.
There is a limit to the number of electrons that can be found in a shell. This can be obtained by a formula 2n² where "n" is the energy level number of the shell.
K: 2n² = 2 × 1² = 2
L: 2n² = 2× 2² = 8
These shells are further subdivided into subshells. There are 4 subshells, s, p, d, and f. Each subshell can hold a different number of electrons.
This electron configuration of carbon can be written as 1s² 2s² 2p² where 1s, 2s, and 2p are the occupied subshells, and the superscript "2" is the number of electrons in each of these subshells.
The value that describe temperature and pressure (STP) is 273.15 K and 101.3 KPa (answer D)
<em><u>Explanation</u></em>
International union of pure and applied chemistry ( IUPAC) established standard temperature and pressure (STP) as below,
temperature 0°c which is the same as 273.15 K
Pressure = 1 atm which is the same = 101.325 KPa or 1.01325 bar
Answer:
a. Put a piece of fresh sliced yam with a bore into it into the soup.
Explanation:
b. Osmosis may occur
