Answer:
Explanation:
Public tap water is not desirable when carrying out experiments in the laboratory.
The chemical definition of water is a compound made up of two atoms of hydrogen to 1 atom of oxygen. Any violation simply desist from the true meaning of water.
Why are tap water not used:
- They contain other dissolved ions like chlorine which have been added in their treatment. This alters the fundamental molecules that is expected to be seen in water. Water of this nature can affect experimental results seriously.
- Tap water can become a mixture instead of a simple compound. A mixture is a combination of several compounds. Such water will have a varied composition and make simplification of experiments very difficult.
Answer:
4.62 M
Explanation:
Molarity = moles/volumes (L), so you need to find the moles and the volumes in liters.
Finding the volume is easy because you just have to convert mL to L, so the volume is 0.45 L
Next, find the moles. You can do this by using the molar mass of aluminum to convert the grams to moles. The molar mass of aluminum is 26.98 g/mol.
56 g * (1 mol/26.98 g) = 2.08 mol
Now, divide the moles (2.08) by the volume (.45 L)
Molarity = 4.62 M
Answer:
The correct answer is: Ka= 5.0 x 10⁻⁶
Explanation:
The ionization of a weak monoprotic acid HA is given by the following equilibrium: HA ⇄ H⁺ + A⁻. At the beginning (t= 0) we have 0.200 M of HA. Then, a certain amount (x) is dissociated into H⁺ and A⁻, as is detailed in the following table:
HA ⇄ H⁺ + A⁻
t= 0 0.200 M 0 0
t -x x x
t= eq 0.200M -x x x
At equilibrium, we have the following ionization constant expression (Ka):
Ka= ![\frac{ [H^{+}] [A^{-} ]}{ [HA]}](https://tex.z-dn.net/?f=%5Cfrac%7B%20%5BH%5E%7B%2B%7D%5D%20%20%5BA%5E%7B-%7D%20%5D%7D%7B%20%5BHA%5D%7D)
Ka= 
Ka= 
From the definition of pH, we know that:
pH= - log [H⁺]
In this case, [H⁺]= x, so:
pH= -log x
3.0= -log x
⇒x = 10⁻³
We introduce the value of x (10⁻³) in the previous expression and then we can calculate the ionization constant Ka as follows:
Ka= 
= 
= 5.025 x 10⁻⁶= 5.0 x 10⁻⁶
Answer:
Explanation:
An atom is the smallest unit of an element that can take part in a chemical reaction. Atoms (and there corresponding symbols) mentioned in the question are
Lithium ⇒ Li
Carbon ⇒ C
Nitrogen ⇒ N
Potassium ⇒ K
Oxygen ⇒ O
Iron ⇒ Fe
Chlorine ⇒ Cl
A compound is substance that contains two or more atoms that are chemically combined and can be represented with a chemical formula. The compounds (and there corresponding formula) mentioned in the question are
Water ⇒ H₂O
Edible salt (sodium chloride) ⇒ NaCl
Chalk (calcium carbonate) ⇒ CaCO₃
Lime (calcium oxide) ⇒ CaO
Iodides (such as sodium iodide and potassium iodide) ⇒ NaI and KI respectively
An: Calculate the molarity of a solution made by adding 120 g of NaOH (40.00 g/mol) to enough water to make 500.0 mL of solution. a) 4.0 M b) 6.0 M c) 1.0 ...
Explanation:
