Answer:
The number of copper atoms 12.405 ×10²³ atoms.
The number of silver atoms 13.13 ×10²³ atoms.
Beaker B have large number of atoms.
Explanation:
Given data:
In beaker A
Number of moles of copper = 2.06 mol
Number of atoms of copper = ?
In beaker B
Mass of silver = 222 g
Number of atoms of silver = ?
Solution:
For beaker A.
we will solve this problem by using Avogadro number.
The number 6.022×10²³ is called Avogadro number and it is the number of atoms in one mole of substance.
While we have to find the copper atoms in 2.06 moles.
So,
63.546 g = 1 mole = 6.022×10²³ atoms
For 2.06 moles.
2.06 × 6.022×10²³ atoms
The number of copper atoms 12.405 ×10²³ atoms.
For beaker B:
107.87 g = 1 mole = 6.022×10²³ atoms
For 222 g
222 g / 101.87 g/mol = 2.18 moles
2.18 mol × 6.022×10²³ atoms = 13.13 ×10²³ atoms
Answer:
Here's what I get.
Explanation:
Quinine contains phosphors, substances that glow when they are hit with certain wavelengths of light.
The phosphors in quinine absorb UV light, which is invisible to our eyes.
Electrons in the phosphors absorb the UV energy and are excited to higher energy levels.
When the electrons drop back to lower energy levels, they emit some of this energy as a glowing blue visible light.
The heat that creates this temperature change coming from change in the internal energy of the system as per as first law of thermodynamics.
<h3>What is Boyle's law ?</h3>
A law stating that the pressure of a given mass of an ideal gas is inversely proportional to its volume at a constant temperature.
As we know, Boyle's law only works when the gas is kept at a constant temperature
Here,
When volume of gases decreased, it means work done has occurred on the system, so the work done is used for raising internal energy of the gas and the other is released as the thermal energy.
So,
According to 1st law of thermodynamics,
we know Q = ΔU + W i.e, change in internal energy and work done. So this is a reason. Changing temperature occurs.
Learn more about Internal enrgy here ;
brainly.com/question/11278589
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Answer:
b
Explanation:
A pure substance has a constant composition and cannot be separated into simpler substances by physical means. There are two types of pure substances: elements and compounds.
Answer : The molar mass of an acid is 266.985 g/mole
Explanation : Given,
Mass of an acid (HX) = 4.7 g
Volume of NaOH = 32.6 ml = 0.0326 L
Molarity of NaOH = 0.54 M = 0.54 mole/L
First we have to calculate the moles of NaOH.
Now we have to calculate the moles of an acid.
In the titration, the moles of an acid will be equal to the moles of NaOH.
Moles of an acid = Moles of NaOH = 0.017604 mole
Now we have to calculate the molar mass of and acid.
Now put all the given values in this formula, we get:
Therefore, the molar mass of an acid is 266.985 g/mole
