Answer:
3.56x10^24 molecules
Explanation:
The following data were obtained from the question:
Mass of Na2SO4 = 840g
Molar Mass of Na2SO4 = (23 x2) + 32 + (16x4) =46 + 12 + 64 = 142g/mol
From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules. This also gives that 1mole of Na2SO4 contains 6.02x10^23 molecules.
If 1 mole (i.e 142g) contains 6.02x10^23 molecules,
Therefore, 840g of Na2SO4 will contain = (840 x 6.02x10^23)/142 = 3.56x10^24 molecules
Answer:
The sharing of electrons between a water molecule that forms four hydrogen bonds with the other four water molecules:
Explanation:
The hydrogen bond is a weak electrostatic force of attraction that exists between a covalently bonded H-atom and a highly electronegative atom like N,O or F.
In the case of the water molecule,
the highly electronegative atom is Oxygen and the intermolecular hydrogen bond in water is as shown below:
Thus H-bond is a weak electrostatic attraction formed between H-atom and O-atom in water.
when the top of the pencil moves in one direction, the bottom end on the ground will move in another, but due to the frictional force it will move by a lesser amount, and the center of mass of the pencil will be accelerated in the horizontal direction due to the force of friction
Answer:
- <u><em>You should expect that the ionic bond in LiBr is stronger than the bond in KBr.</em></u>
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Explanation:
The<em> ionic bonds</em> are formed by the electrostatic attraction between the ions, cations and anions.
In KBr the cation is K⁺ and the anion is Br⁻.
In LiBr the cation is Li⁺ and the anion is Br⁻.
You must expect that the bond strength depends mainly on the charges present on each ion and the distance between them.
Nevertheless, the effect of the distance between the radius dominate the trendency of the bond strength, which makes that the ionic strength trend be related to the ionic radius trend.
Lithium is a smaller ion than Potassium (both are in the same group and Lithium is above Potassium).
Thus, you should expect that the Li ion is closer to the Br ion than what the K ion is to the Br ion and expect that the bond between a Li ion and the Br ion be stronger than the bond between the K ion and the Br ion.
Answer:
15.24 J is the change in internal energy for this process.
Explanation:
According to the first law of thermodynamics:-
Where,
U is the internal energy
q is the heat
w is the work done
From the question,
q = + 75 J
(+ sign as the heat is being absorbed)
The expression for the calculation of work done is shown below as:
Where, P is the pressure
is the change in volume
From the question,
= 2.00 - 1.40 L = 0.60 L
P = 1.02 atm
Also, 1 atmL = 101.3 J
So,
(work is done by the system)
So,
<u>15.24 J is the change in internal energy for this process.</u>
