Answer:
A heater warming a room
Explanation:
The reason is that thermal energy is heat. The first option is the only one that has heat in it. A flashlight shining in a wall shows light energy. A football flying through the air shows potential energy to kinetic energy. A radio playing a song shows sound energy. The only answer that shows thermal energy is the first one. I hope I was able to help! :)
if people like the smell of burning wood, then they would not like the smell of gasoline
Explanation:
it's a supposition without any real truth to back it up
Answer:
Option A, The pH of the solution is 2.7 and the solution is acidic
Explanation:
As we know,
pH = - log [H3O+]
Substituting the given values, we get
pH = - log [2.1 x 10-3 M]
pH = - (-2.678)
pH = 2.678 or 2.7
The solution is acidic as pH value is less than 7
Hence, option A is correct
Answer:
6.82g
0.59moles
Explanation:
1. What is the mass sample of 0.0500 moles of zinc chloride ?
Given parameters:
Number of moles ZnCl₂ = 0.05moles
Unknown:
Mass of the sample = ?
Solution:
To find the mass of a substance using the number of moles, it would be pertinent to understand what mole is.
A mole is a substance that contains the avogadro's number of particles.
It relates to the mass using the expression below;
Mass of a substance = number of moles x molar mass
Molar mass of ZnCl₂;
Atomic mass of Zn = 65.4g/mol
Cl = 35.5g/mol
Molar mass = 65.4 + 2(35.5) = 136.4g/mole
Mass of a substance = 0.05 x 136.4 = 6.82g
2. How many moles of potassium sulfide are in a 65.50g sample?
Given parameters:
Mass of K₂S = 65.5g
Unknown:
Number of moles = ?
Solution:
The number of moles of any substance is related to mass using the expression below;
Number of moles = 
Molar mass of K₂S = 2(39) + 32 = 110g/mol
Number of moles =
= 0.59moles