Citric acid has the molecular formula C6H8O7 so you can add the molar masses of the elements from the periodic table. C has a molar mass of 12.01 g/mol, H has 1.01 g/mol and O has 15.999 g/mol. Now you calculate the total molar mass= (6*12.01 + 8*1.01 + 7*15.999). This yields a molar weight of 192.124 g/mol (anhydrous)
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
Explanation:
Beryllium is a group 2 element and its atomic number is 4. Electronic configuration of beryllium is
.
Since, a beryllium contains two valence electrons so, in order to attain stability it will readily lose its 2 valence electrons.
Therefore, a beryllium atom upon losing two valence electrons will acquire a +2 charge.
Thus, we can conclude that the net ion charge of Beryllium is +2.
Answer:
runoff is he draining away of water (or substances carried in it) from the surface of an area of land, a building or structure, etc.
Explanation:
Answer:
d. Temperature and number of molecules of gas
Step-by-step explanation:
Boyle's Law states, "The volume of a fixed mass of a gas is inversely proportional to the pressure if the temperature remains constant."
Let's examine the words.
"… volume…is inversely proportional to the pressure …" This means that volume and pressure are the <em>variables</em>.
"… fixed mass of a gas …" means that the number of molecules is constant.
"… temperature remains constant" speaks for itself.
a, c, and e are <em>wrong</em>, because pressure is a variable.
b is <em>wrong</em>, because volume is a variable.