Answer:
0.877 mol
Step-by-step explanation:
We can use the<em> Ideal Gas Law </em>to solve this problem.
pV = nRT Divide both sides by RT
n = (pV)/(RT)
Data:
p = 646 torr
V = 25.0 L
R = 0.082 06 L·atm·K⁻¹mol⁻¹
T = 22.0 °C
Calculations:
(a) <em>Convert the pressure to atmospheres
</em>
p = 646 torr × (1 atm/760 torr) = 0.8500 atm
(b) <em>Convert the temperature to kelvins
</em>
T = (22.0 + 273.15) K = 295.15 K
(c) <em>Calculate the number of moles
</em>
n = (0.8500 × 25.0)/(0.082 06 × 295.15)
= 0.877 mol
Explanation:
1. Explain how groups 1A-8A in the periodic table are organized by their number of valence electrons.
The valence electrons in an atom are the outermost shell electrons. They are the most loosely held electrons in an atom.
Coincidentally, the periodic table of elements divided into vertical groups and horizontal periods can be said to be arranged according to the number of valence electrons.
- Atomic numbers are used to arrange elements on the periodic table.
- Down a group, the number of electronic shell increases. More electrons are added to new energy levels.
- As we move from left to right across a period, the number of electrons in elements increases but electronic shell is the same.
- Down a group electronic shell increases but the number of valence electrons are the same.
- All elements in Group 1A has just one valence electrons, Group 2A has two valence electrons.........Group 8A has eight valence electrons.
- Moving across groups is synonymous to moving from left to right on the periodic table.
- Due to this trend, the periodic table is arranged based on the number of valence electrons.
3. explain how you know the number of valence electrons for each group.
The number of valence electrons in a group is the group number:
Group Number valence electrons
1A 1
2A 2
3A 3
4A 4
5A 5
6A 6
7A 7
8A 8
learn more:
Periodic table brainly.com/question/1971327
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Answer: a) The concentration after 8.8min is 0.17 M
b) Time taken for the concentration of cyclopropane to decrease from 0.25M to 0.15M is 687 seconds.
Explanation:
Expression for rate law for first order kinetics is given by:
where,
k = rate constant
t = age of sample
a = let initial amount of the reactant
a - x = amount left after decay process
a) concentration after 8.8 min:
b) for concentration to decrease from 0.25M to 0.15M
Answer:
The molarity is 0.56
Explanation:
In a mixture, the chemical present in the greatest amount is called a solvent, while the other components are called solutes. Then, the molarity or molar concentration is the number of moles of solute per liter of solution.
In other words, molarity is the number of moles of solute that are dissolved in a given volume.
The Molarity of a solution is determined by:
Molarity is expressed in units ().
Then you must know the number of moles of Cu(NO₂)₂. For that it is necessary to know the molar mass. Being:
-
Cu: 63.54 g/mol
- N: 14 g/mol
- O: 16 g/mol
the molar mass of Cu(NO₂)₂ is:
Cu(NO₂)₂= 63.54 g/mol + 2*(14 g/mol + 2* 16 g/mol)= 155.54 g/mol
Now the following rule of three applies: if 155.54 g are in 1 mole of the compound, 225 g in how many moles are they?
moles= 1.45
So you know:
- number of moles of solute= 1.45 moles
- volume=2.59 L
Replacing in the definition of molarity:
Molarity= 0.56
<u><em>The molarity is 0.56</em></u><u><em></em></u>
Answer:
The combination of nuclei to form a bigger and heavier nucleus is known as Fussion. The consequence of fusion is the absorption or release of energy.