Answer:
Mass = 208.26 g
Explanation:
Given data:
Volume of water = 40.0 mL
Volume of water + copper = 63.4 mL
Volume of copper = ?
Density of copper = 8.9 g/cm³
Mass of copper = ?
Solution:
Volume of copper:
Volume of copper = (Volume of water + copper ) - Volume of water
Volume of copper = 63.4 mL - 40.0 mL
Volume of copper = 23.4 mL
Mass of copper:
density = mass/volume
8.9 g/cm³ = mass/23.4 mL
cm³ = mL
Mass = 8.9 g/mL × 23.4 mL
Mass = 208.26 g
a) Gas particles have most of their mass concentrated in the nucleus of the atom.
b) The moving particles undergo perfectly elastic collisions with the walls of the container.
c) The forces of attraction and repulsion between the particles are insignificant.
d) The average kinetic energy of the particles is directly proportional to the absolute temperature.
e) All of the above are postulates of the kinetic molecular theory.
Gas particles have most of their mass concentrated in the nucleus of the atom.
Answer: Option A.
<u>Explanation:</u>
Kinetic Molecular Theory expresses that gas particles are in consistent movement and show flawlessly versatile crashes. Motor Molecular Theory can be utilized to clarify both Charles' and Boyle's Laws. The normal active vitality of an assortment of gas particles is straightforwardly corresponding to total temperature as it were.
The kinetic theory of gases is a significantly critical, however straightforward model of the thermodynamic conduct of gases with which numerous important ideas of thermodynamics were built up.
Answer:
[HAc] = 0.05M
[Ac⁻] = 0.20M
Explanation:
The Henderson-Hasselbalch formula for the acetic acid buffer is:
pH = pka + log₁₀ [Ac⁻] / [HAc]
Replacing:
5.36 = 4.76 + log₁₀ [Ac⁻] / [HAc]
3.981 = [Ac⁻] / [HAc] <em>(1)</em>
Also, as total concentration of buffer is 0.25M it is possible to write:
0.25M = [Ac⁻] + [HAc] <em>(2)</em>
Replacing (2) in (1)
3.981 = 0.25M - [HAc] / [HAc]
3.981 [HAc] = 0.25M - [HAc]
4.981 [HAc] = 0.25M
<em>[HAc] = 0.05M</em>
Replacing this value in (2):
0.25M = [Ac⁻] + 0.05M
<em>[Ac⁻] = 0.20M</em>
I hope it helps!
Physical change!
a solid that turns into a liquid is called melting and melting is a physical change.
something like that. sorry if it’s wrong
Answer:
Mass = 2.89 g
Explanation:
Given data:
Mass of NH₄Cl = 8.939 g
Mass of Ca(OH)₂ = 7.48 g
Mass of ammonia produced = ?
Solution:
2NH₄Cl + Ca(OH)₂ → CaCl₂ + 2NH₃ + 2H₂O
Number of moles of NH₄Cl:
Number of moles = mass/molar mass
Number of moles = 8.939 g / 53.5 g/mol
Number of moles = 0.17 mol
Number of moles of Ca(OH)₂ :
Number of moles = mass/molar mass
Number of moles = 7.48 g / 74.1 g/mol
Number of moles = 0.10 mol
Now we will compare the moles of ammonia with both reactant.
NH₄Cl : NH₃
2 : 2
0.17 : 0.17
Ca(OH)₂ : NH₃
1 : 2
0.10 : 2/1×0.10 = 0.2 mol
Less number of moles of ammonia are produced by ammonium chloride it will act as limiting reactant.
Mass of ammonia:
Mass = number of moles × molar mass
Mass = 0.17 mol × 17 g/mol
Mass = 2.89 g
