Answer:
54 grams ammonium chloride and 40 grams sodium hydroxide
Explanation:
A buffer is a solution that contains either a weak acid and its salt or a weak base and its salt, the solution is resistant to changes in pH. This means that, a buffer is an aqueous solution of either a weak acid and its conjugate base or a weak base and its conjugate acid.
A Buffer is used to maintain a stable pH in a solution, buffers can neutralize small quantities of additional acid of base. For any buffer solution, there is always a working pH range and a set amount of acid or base that can be neutralized before the pH will change. The amount of acid or base that can be added to a buffer before changing its pH is called its buffer capacity.
A good buffer mixture is supposed to have about equal concentrations of its both components. It is a rule of thumb therefore, that a buffer solution has generally lost its usefulness when one component of the buffer pair is less than about 10% of the other component.
The implication of this is that the ammonium chloride and sodium hydroxide should be of approximately the same concentration. If the masses are dissolved as shown in the answer, then we will have 1molL-1 of each component of the buffer in accordance with the rule of thumb stated above.
Answer:
The molar mass of Mg(NO₃)₂, 148.3 g/mol.
Explanation:
Step 1: Given data
- Mass of Mg(NO₃)₂ (solute): 42.0 g
- Volume of solution: 259 mL = 0.259 L
Step 2: Calculate the moles of solute
To calculate the moles of solute, we need to know the molar mass of Mg(NO₃)₂, 148.3 g/mol.
42.0 g × 1 mol/148.3 g = 0.283 mol
Step 3: Calculate the molarity of the solution
M = moles of solute / liters of solution
M = 0.283 mol / 0.259 L
M = 1.09 M
Answer:
Convention currents are found in the asthenosphere part present in the mantle of the Earth.
Explanation:
The Mantle is the middle layer of the earth surface extending up to 2900 kilometers.
Beneath the Mantle lies the core which contains molten rocks and materials called magma.
The materials are highly radioactive and immensely heated. These highly hot condition creates pressure on the middle layer (Mantle).
As a result, large convention currents are generated excessively
Answer:
In order to keep propane a liquid at room temperature (70° F or 21° C), it has to be held in a tank at a pressure of about 850 kPa. ... Household metal tanks cannot withstand this pressure. In short, natural gas is not stored in household tanks because the symmetry of its molecule makes it hard to liquify.
Answer:
19. 1, 2, 3, 4, 5, 6, 7, 8
20. Li=1+, Be=2+, B=3+, C=4+
21. N=3-, O=2-, F=1-
Explanation: