Answer:
1.03 grams of hydrogen is produced from 12.5 g of Mg reacting with hydrochloric acid.
Explanation:
The balanced reaction is:
Mg+ 2 HCl → MgCl₂ + H₂
By stoichiometry of the reaction, the following amounts of moles of each compound participate in the reaction:
- Mg: 1 mole
- HCl: 2 moles
- MgCl₂: 1 mole
- H₂: 1 mole
Being the molar mass of each compound:
- Mg: 24.31 g/mole
- HCl: 36.45 g/mole
- MgCl₂: 95.21 g/mole
- H₂: 2 g/mole
By reaction stoichiometry, the following mass amounts of each compound participate in the reaction:
- Mg: 1 mole* 24.31 g/mole= 24.31 g
- HCl: 2 moles* 36.45 g/mole= 72.9 g
- MgCl₂: 1 mole* 95.21 g/mole= 95.21 g
- H₂: 1 mole* 2 g/mole= 2 g
Then you can apply the following rule of three: if by stoichiometry 24.31 grams of Mg produces 2 grams of H₂, 12.5 grams of Mg produces how much mass of H₂?
mass of H₂= 1.03 grams
<u><em>1.03 grams of hydrogen is produced from 12.5 g of Mg reacting with hydrochloric acid.</em></u>
Answer:
[H⁺] = 5.011 × 10⁻³ mol.L⁻¹
Explanation:
The pH is converted into concentration of H⁺ as,
[H⁺] = 10^-pH
Where 10 is antilog,
So, putting values,
[H⁺] = 10⁻²·³
[H⁺] = 0.00501
Or,
[H⁺] = 5.011 × 10⁻³ mol.L⁻¹
Answer:
37 mmol of acetate need to add to this solution.
Explanation:
Acetic acid is an weak acid. According to Henderson-Hasselbalch equation for a buffer consist of weak acid (acetic acid) and its conjugate base (acetate)-
![pH=pK_{a}(acetic acid)+log[\frac{mmol of CH_{3}COO^{-}}{mmol of CH_{3}COOH }]](https://tex.z-dn.net/?f=pH%3DpK_%7Ba%7D%28acetic%20acid%29%2Blog%5B%5Cfrac%7Bmmol%20of%20CH_%7B3%7DCOO%5E%7B-%7D%7D%7Bmmol%20of%20CH_%7B3%7DCOOH%20%7D%5D)
Here pH is 5.31, 
(acetic acid) is 4.74 and number of mmol of acetic acid is 10 mmol.
Plug in all the values in the above equation:
![5.31=4.74+log[\frac{mmol of CH_{3}COO^{-}}{10}]](https://tex.z-dn.net/?f=5.31%3D4.74%2Blog%5B%5Cfrac%7Bmmol%20of%20CH_%7B3%7DCOO%5E%7B-%7D%7D%7B10%7D%5D)
or, mmol of 
= 37
So 37 mmol of acetate need to add to this solution.
Wavelength have an indirect relationship with frequency. Since gamma rays have the shortest wavelength, then they have the highest frequency. As the wavelength shortens, the frequency heightens.
Radio waves for example, have the longest wavelength, so it is expected that they have lowest frequencies.
Answer:
an alloy is a mixture of elements that has metallic properties
Explanation:
