Answer:
Molarity of potassium chloride is:
A. 1.0 M
Explanation:
Molarity is used to express the concentration of the solution.It is defined as the moles of solutes per liter volume of solution.It is denoted by M.
Here'n' is the number of moles. It can be calculated using formula:
given mass=30 gm
Molar mass of KCl = mass of K+mass of Cl
= 39.098+34.45
= 74.55 g
n = 0.402 moles
M=1.00 M
So molarity of potassium chloride is 1.00 M
Answer:
0,218 moles
Explanation:
I will first explain how many liters is 256ml, that is 0,256 l.
because the m stands for milli which is a factor of 1000 -> (256 ml / 1000 = 0,256 l)
To calculate the amount of moles you multiply the volume with the concentration. So 0,256l x 0,855M = 0,218 moles.
Answer:
d. 380g
Explanation:
The reaction of production of hydrogen from zinc and HCl is:
Zn + 2HCl → ZnCl₂ + H₂(g)
At STP (1atm of pressure and 273.15K), 112L are:
n = PV /RT
n = 1atm×112L / 0.082atmL/molK×273.15K
<em>n = 5.00 moles </em>
That means you need to produce 5.00 moles of hydrogen. Based on the reaction, 1 mole of Zn produce 1 mole of H₂(g), as yield of reaction is 85%:
5.00 moles H₂(g) ≡ 5.00 moles of Zn / 85% = <em>5.88 moles of Zn you need</em>
As molar mass of Zn is 65.38 g/mol:
5.88 moles Zn × (65.38g /mol) = 384 g of Zn ≡ <em>d. 380g</em>
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I hope it helps!
Answer:
Calcite
Explanation:
The chart shows that calcite is higher than gypsum, but is lower than apatite. Therefore meaning that it can scratch gypsum But not able to the same to apatite.
Answer:
1.37x10²⁵atoms of carbon
2.74x10²⁵ atoms of oxygen.
33.7g of KNO₃
Explanation:
To answer this question you must use molar mass of carbon dioxide (44g/mol) and 1 mole are 6.022x10²³atoms.
1.00kg are 1000g of CO₂. Moles are:
1000g CO₂ * (1mol / 44g) = 22.73 moles of CO₂ = 22.73 moles of carbon.
In atoms:
22.73 moles C * (6.022x10²³atoms / 1mole) = 1.37x10²⁵atoms of carbon
There are 22.73 moles of CO₂ * 2 = 45.45 moles of oxygen are present in the carbon dioxide. In atoms:
45.45 moles Oxygen * (6.022x10²³atoms / 1mole) = 2.74x10²⁵ atoms of oxygen.
1 mole of Potassium nitrate, KNO₃, contains 3 moles of oxygen. 1 mol of oxygen are:
1.00 mol O * (1mol KNO₃ / 3 moles O) = 0.33 moles of KNO₃
As molar mass of KNO₃ is 101.1g/mol:
0.33 moles of KNO₃ * (101.1g / mol) = 33.7g of KNO₃
