Answers
Answer:
1.62 g
Explanation:
Given that:
Concentration of HCN = 0.119 M
Assuming the ka 4.00 × 10⁻¹⁰
The pKa of HCN (hydrocyanic acid) = -log (Ka)
= - log ( 4.00 × 10⁻¹⁰)
= 9.398
pH of buffer = 8.809
Using Henderson Hasselbach equation:
[CN^-] = 0.2576[HCN]
[CN^-] = 0.2756 (0.119) L
[CN^-] = 0.033 M
∴
The amount of NaCN (sodium cyanide) is calculated as follows:
= 1.62 g
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What is the principal reason we must consider the uncertainty principle when discussing electrons and other subatomic particles but not when discussing our macroscopic world?
Towards the sun
Answers
Answer:
This happens twice a year during Earth's orbit. Near June 21 the north pole is tilted 23.5 degrees toward our Sun and the northern hemisphere experiences summer solstice, the longest day of the northern hemisphere year.
...
Do other planets have seasons?
Uranus
30,589
97.8
Spring Equinox* 2050
Summer Solstice*
points toward the sun.
closer the earth is to the sun the more hot it will be the closer it is to summer,
you can see at D northern hemisphere is closest to sun and the north pole is pointing toward the sun.
Answers
Answer:
124 g (3 sig figs)
or
124.011 g (6 sig figs
Explanation:
Step 1: Calculate g/mol for AgNO₃
Ag - 107.868 g/mol
N - 14.01 g/mol
O - 16.00 g/mol
107.868 + 14.01 + 16.00(3) = 169.878 g/mol
Step 2: Multiply 0.73 moles by molar mass
0.73 mol (169.979 g/mol)
124 grams of AgNO₃
Answers
Answer:
Option (A) saturated and is at equilibrium with the solid KCl
Explanation:
A saturated solution is a solution which can not dissolve more solute in the solution.
From the question given above, we can see that the solution is saturated as it can not further dissolve any more KCl as some KCl is still visible in the flask.
Equilibrium is attained in a chemical reaction when there is no observable change in the reaction system with time. Now, observing the question given we can see that there is no change in flask as some KCl is still visible even after thorough shaking. This simply implies that the solution is in equilibrium with the KCl solid as no further dissolution occurs.
Answers
Answer:
A range of organic molecules can undergo combustion. Pyridine (C5H5 combustion in the unbalanced reaction shown below wtar o 4 CsH5N + O2 +H2O + CO2 + NO a) Write the balanced equation. (2 points) # 41 CH N +170 70 the flow, t- b) Find the percent yield for the reaction if 10.0 g of pyridine dioxide. (2 points)
Explanation:
hope this helps!
Answers
Answer:
3,8×10⁻⁵ mol/L of potassium permanganate solution
Explanation:
To calculate concentration in mol/L you must convert the 3,8 umol to moles and 100 mL to liters, knowing 1 umol are 1×10⁻⁶mol and 1L are 1000 mL.
3,8 umol × (1×10⁻⁶mol / 1 umol ) = 3,8×10⁻⁶mol of potassium permanganate.
100 mL × ( 1L / 1000 mL) = 0,100 L
Thus, concentration in mol/L is:
3,8×10⁻⁶mol / 0,100 L = 3,8×10⁻⁵ mol/L of potassium permanganate solution
I hope it helps!
Answers
61.8 % is the mass percentage of magnesium sulphate.
Explanation:
The mass percent of individual solute or ion in a compound is calculated by the formula:
Grams of solute ÷ grams of solute + solvent × 100
mass percent of magnesium is calculated as 1 mole of magnesium having 24.305 grams/mole will have weight of 24.305 grams and 1 mole of MgSO4 will have 120.366 grams
Putting the values in the equation:
24.305 ÷ 144.671 × 100
= 16.8% of magnesium is in the mixture
The mass percentage of SO4 is calculated as
= 96.06 ÷ 216.426 × 100
= 44.38 %
The mass percentage of the mixture MgSO4 is 44.38 + 16.8 = 61.8 %
Mass percentage is a representation of the concentration of element or elements in a compound.