Answer:

Explanation:
The first step is to calculate the molar mass of H₂O:

So, 1 mol has a mass of 18.02 g.
Next you calculate the mass of 3.2 mol of H₂O

<span>Answer for the given question is CaBr2.
Although, the given equation requires balancing of by adding one more HBr and one more H2o in resultant. The given equation will product at least one CaBr2. Hence the answer for the given equation is Calcium bromide i.e. CaBr2.</span>
The question is incomplete, complete question is :
Determine the pH of an HF solution of each of the following concentrations. In which cases can you not make the simplifying assumption that x is small? (
for HF is
.)
[HF] = 0.280 M
Express your answer to two decimal places.
Answer:
The pH of an 0.280 M HF solution is 1.87.
Explanation:3
Initial concentration if HF = c = 0.280 M
Dissociation constant of the HF = 

Initially
c 0 0
At equilibrium :
(c-x) x x
The expression of disassociation constant is given as:
![K_a=\frac{[H^+][F^-]}{[HF]}](https://tex.z-dn.net/?f=K_a%3D%5Cfrac%7B%5BH%5E%2B%5D%5BF%5E-%5D%7D%7B%5BHF%5D%7D)


Solving for x, we get:
x = 0.01346 M
So, the concentration of hydrogen ion at equilibrium is :
![[H^+]=x=0.01346 M](https://tex.z-dn.net/?f=%5BH%5E%2B%5D%3Dx%3D0.01346%20M)
The pH of the solution is ;
![pH=-\log[H^+]=-\log[0.01346 M]=1.87](https://tex.z-dn.net/?f=pH%3D-%5Clog%5BH%5E%2B%5D%3D-%5Clog%5B0.01346%20M%5D%3D1.87)
The pH of an 0.280 M HF solution is 1.87.
Answer: B) Electromagnetic waves can travel through empty space.
Explanation:
Conduction: This type of heat transfer happens when there is direct contact between the two object. Example: heating a pan on stove.
Convection: This type of heat transfer happens when there is a movement of fluid (liquid or gas) due to the movement of hot layers to the top and cold layers to the bottom which leads to convection currents. Example: Heating of swimming pool.
Radiation: This type of heat transfer happens when there is direct transfer of energy through empty space.The electromagnetic radiation from the surface of an object which is due to the object's temperature is radiation. Example: Heating of earth's surface.
<span>an oxide of iron, magnesium, aluminum, and chromium</span>