A buffer is a solution of weak acid and conjugate base or weak base and conjugate acid used to resist pH change with added solute. <span />
Answer:
d
. Sc2O5
Explanation:
Hello,
In this case, when forming oxides from a metal and oxygen, for us to find out each element's subscript, we must exchange them as shown below, considering +5 for scandium:

For that reason, the answer is d
. Sc2O5
Best regards.
Hydroxide ions are what you are looking for. When hydroxide ions are released, the solution becomes more basic
Answer:
Hydrogen bonding
Explanation:
As a rule of thumb, "likes dissolve like", meaning polar solutes dissolve in polar solvents and nonpolar solutes in nonpolar solvents. In this case, water is polar (<em>dipolar moment</em> = 1.85 Debye) dissolves methanol which is also polar (<em>dipolar moment</em> = 1.69 Debye). Besides being dipoles, both molecules have atoms of Hydrogen with a covalent bond to more electronegative atoms of Oxygen. When this happens, stronger dipole-dipole interactions appear known as Hydrogen bonding. There is an electrostatic attraction between H (positive charge density) and O (negative charge density).
FeCO3 ==> Fe + produsi minoritari.
m Fe impur= 700 kg
puritatea (p) = masa pura (mp)/ masa impura (mi) x 100
mp= p x mi / 100 sau mp = p/100 x mi => mp Fe = 90/100 x 700 = 630 kg Fe pur.
M FeCO3= 115.85 kg/kmol
115.85 kg FeCO3 .... 55.85 kg Fe
x kg FeCO3 ........630 kg Fe
x= 630 * 115.85 /55.85 = 1306.81 kg FeCO3 (mp in formula puritatii)
p=mp/mi x 100
mi FeCO3 = 1500 kg
mp FeCO3=1306.81 kg
p=1306.81 / 1500 x 100 = 87.12% puritate Siderit