In the context of chemistry, yes. Energy input is always equal to the energy output.
Answer:
Explanation:
scheelite is CaWO₄
Mol weight = 288
80 g of scheelite = 80 / 288 = 27.77 x 10⁻² moles
27.77 x 10⁻² moles of scheelite = 27.77 x 10⁻² x 6.02 x 10²³ molecules of scheelite
= 167.17 x 10²¹ molecules of scheelite
1 molecule of scheelite contains 4 atoms of oxygen
167.77 x 10²¹ molecules of scheelite contains 4 x 167.77 x 10²¹ atoms of oxygen .
= 671.08 x 10²¹ atoms of oxygen .
= 671 x 10²¹ atoms .
Answer:
- <em>Option D. temperature</em>
Explanation:
Indeed it is generally established that <em>temperature is a measure of the kinetic energy ot the particles</em>.
The <em>kinetic energy</em> of a particle is proportional to the product of the mass and the square of the speed. Mathematically, the kinetic energy, KE, is:
Where m is the mass and v the speed of the particle.
In a sample of matter, not all the particles have the same speed, hence not all the particles have the same kinetic energy.
The kinetic energy and the temperature are related by the Boltzman equation:
Where K is a constant (Boltzman constant) and T is the absolute temperature.
Therefore, as you can see from the last equation, <em>the temperaure is a measure of the averate kinetic energy of the particles in a sample of matter</em>.
This is, at a certain temperature, every substance has the same average kinetic energy.
The number of molecules that are in balloon are = 2.227 x10^23 molecules
<h3> calculation</h3>
calculate the number of moles of NO
moles = mass/molar mass
molar mass of NO = 14+ 16 = 30 g/mol
moles is therefore= 11.1 g/30g/mol= 0.37 moles
by use of Avogadro's constant that is
1 mole= 6.02 x10^23 molecules
0.37 =? molecules
=(6.02 x10^23 x 0.37 moles)/ 1mole=2.227 x10^23 molecules
Answer:
3.91 × 10⁴ J/mol
Explanation:
We can calculate the heat of solution using the following expression.
Q = c × m × ΔT
where,
c is the specific heat capacity of the solution
m is the mass of the solution
ΔT is the change in the temperature
The mass of LiCl is:
The mass of the solution is:
m = mLiCl + mH₂O = 10.6 g + 200.0 g = 210.6 g
Q = c × m × ΔT = (4.184 J g⁻¹ °C⁻¹) × 210.6 g × 11.08 °C = 9763 J
In a constant pressure calorimeter, the molar enthalpy of solution for LiCl is:
