25.9 kJ/mol. (3 sig. fig. as in the heat capacity.)
<h3>Explanation</h3>
The process:
.
How many moles of this process?
Relative atomic mass from a modern periodic table:
- K: 39.098;
- N: 14.007;
- O: 15.999.
Molar mass of 
:
.
Number of moles of the process = Number of moles of dissolved:
.
What's the enthalpy change of this process?
for 
. By convention, the enthalpy change 
measures the energy change for each mole of a process.
.
The heat capacity is the least accurate number in these calculation. It comes with three significant figures. As a result, round the final result to three significant figures. However, make sure you keep at least one additional figure to minimize the risk of rounding errors during the calculation.
Answer:
Option c and d
Explanation:
John Dalton. In 1808, John Dalton proposed a theory known as Dalton’s Atomic Theory. The theory was published in a paper titled “A New Chemical Philosophy”. This theory was new to that era
The 5 postulates of Daltons' atomic theory are:
1. All the matters are made of atoms.
2. Atoms of different elements combine to form compounds
3. Compounds contain atoms in small whole-number ratios
4. Atoms can neither be created nor destroyed
. (This was later proven wrong )
5. All atoms of an element are identical and have the same properties (This was later proven wrong as atoms of same element may be different in case of elements having isotopes )
Therefore, options c and d are the answer.
Answer:
2.76 × 10⁻¹¹
Explanation:
I don’t have access to the ALEKS Data resource, so I used a different source. The number may be different from yours.
1. Calculate the free energy of formation of CCl₄
C(s)+ 2Cl₂(g)→ CCl₄(g)
ΔG°/ mol·L⁻¹: 0 0 -65.3
ΔᵣG° = ΔG°f(products) - ΔG°f(reactants) = -65.3 kJ·mol⁻¹
2. Calculate K
T = (25.0 + 273.15) K = 298.15 K
Answer:
Number of proton is 11
Number of neutrons is 12
Number of electrons is 10
Explanation:
For a neutral Na, Sodium atom:
The mass number P+N = 23
Atomic number(E or P) = 11
A charged Na atom that has lost an electron is positively charged and so:
Number of proton = 11 (Still the same)
Number of neutrons = 12
Number of electrons = 11-1=10 (the atom has lost an electron)
If an atom loses electron, it becomes positively charged ie P>E
Answer:
The correct answer is the option c)He thought the mold had released a chemical that prevented the bacteria’s growth.
Explanation:
In the 1920s, Alexander Fleming was working in his laboratory at St. Mary's Hospital in London when, almost by accident, he discovered a naturally growing substance that could attack certain bacteria. In one of his experiments, Fleming observed that colonies of a bacterium had been depleted or removed by a mold that grew on the same Petri dish. He observed that the bacteria furthest from the fungus had grown to produce large-sized colonies, while the colonies closest to the fungus were tiny. He determined that mold made a substance that could dissolve bacteria. The fungus was penicilium chrysogenum and thus Fleming called this substance penicillin, by the name of the mold that produces it. Thus, after several years of experiments in 1930, Howard Florey and Ernest Chain developed at Oxford University the procedures to produce pure penicillin from the fungus that Fleming isolated. Thus penicillin could be concentrated by Florey and Chain, and in 1945 they shared with Fleming the Nobel Prize in Medicine.
Then, <u><em>the correct answer is the option c)He thought the mold had released a chemical that prevented the bacteria’s growth.</em></u>
