Answer:
Brainliest pls
Explanation:
1 mole of a substance contains Avagadro’s number of particles,
i.e. 6.023*10^23
By unitary method,
5 moles of oxygen contains 5 times the Avagadro’s number of particles
i.e. 5* (6.023*10^23) = 3.0115*10^24 number of particles.
Now, the further answer depends on what particles the question concentrates on.
If number of atoms are asked , the above answer must be multiplied by 2, because oxygen is a diatomic gas and each atom contributes to be a particle.
therefore, 5 moles of oxygen has 6.023*10^24 atoms.
If number of molecules asked, the above answer is directly written...
They are different measurements
15% = 15 grams of solute in 100 mL solution
15 g --------------- 100 mL
?? ------------------ 1000 mL
1000 x 15 / 100 =
15000 / 100 => 150 g of solute
hope this helps!
Answer:
The mass of ice required to melt to lower the temperature of 353 mL of water from 26 ⁰C to 6 ⁰C is 85.4197 kg
Explanation:
Heat gain by ice = Heat lost by water
Thus,
Heat of fusion + 
Where, negative sign signifies heat loss
Or,
Heat of fusion + 
Heat of fusion = 334 J/g
Heat of fusion of ice with mass x = 334x J/g
For ice:
Mass = x g
Initial temperature = 0 °C
Final temperature = 6 °C
Specific heat of ice = 1.996 J/g°C
For water:
Volume = 353 mL
Density of water = 1.0 g/mL
So, mass of water = 353 g
Initial temperature = 26 °C
Final temperature = 6 °C
Specific heat of water = 4.186 J/g°C
So,
345.976x = 29553.16
x = 85.4197 kg
Thus,
<u>The mass of ice required to melt to lower the temperature of 353 mL of water from 26 ⁰C to 6 ⁰C is 85.4197 kg</u>
Answer:
c. Only certain energies are allowed for the electron in a hydrogen atom
Explanation:
Emission spectrum are produced when the excited electron in a atom release the energy in the form of photons to come to ground state. These photons are of different wavelengths depending on the excitation state of emitting electron or transition of electron. These electromagnetic radiation are observed through prism to produce the spectrum.
As the name indicates this spectrum is produced by emission of energy. Although the electron can be excited by different methods such as by heating but the key point is that electrons in hydrogen atom will emit the photons of same energy which they absorb and each electron can absorb only certain type of energy. So four lines were observed in the visible spectrum of hydrogen because only certain energies are observed for hydrogen atom.
