The answer is:
a. 0.712 M
b. 0.210 M
c. 0.336 M
Molarity is a measure of the concentration of solute in a solution.
It can be expressed as moles of solute ÷ volume of solution:
c = n ÷V
where:
c - concentration of solute,
n - moles of solute
V - volume of solution
n can be expressed as:
<span>n = m ÷ Mr
</span>where:
<span>n - moles of solute
</span>m - mass of solute
Mr - relative molecular mass
a. We know volume:
V = 289.2 mL = 0.2892 L
We need n and c.
n = m ÷ Mr
m = 15.4 g
Mr (<span>KCl) = 74.55 g/mol
n = </span>15.4 g ÷ <span>74.55 g/mol
n = 0.206 mol</span>
Thus,
c = 0.206 mol ÷ <span>0.2892 L
c = 0.712 mol/L = 0.712 M
</span>b. We know volume:
V = 0.614 L
We need n and c.
n = m ÷ Mr
m = 14.4 g
Mr (CaCl₂<span>) = 110.98 g/mol
n = </span>14.4 g ÷ <span>110.98 g/mol
n = 0.129 mol</span>
Thus,
c = 0.129 mol ÷ <span>0.614 L
c = 0.210 mol/L = 0.210 M
</span>
c. We can use formula:
m₁V₁ = m₂V₂
<span>m₁ = 3 M
</span><span>V₁ = 28 mL= 0.028 L
</span><span>m₂ = ?
</span><span>V₂ = 0.250 L
</span>Thus:
3 M × 0.028 L = m₂× <span>0.250 L
</span> m₂ = 0.336 M
Answer:
I’ll give you two possible conditions:
(1) An acid is present in an aqueous solution. The acid will donate a proton to the water to form hydronium. (That’s not really what happens, but that’s how we usually think of it.)
(2) The autoionization of water: in a pure water solution (or not a pure solution, doesn’t matter), one water molecule donates a proton to another water molecule, forming equal numbers of hydronium and hydroxide ions.
The equation is given is of combustion of ethanol.
Fuel ethanol (C2H5OH) has high energy carbon-carbon (C-C) and carbon-hydrogen (C-H) bonds that store chemical energy. From the ethanol container, ethanol molecules evaporating, enter the flame's base. A physical action called evaporation converts liquid into gas. Ethanol evaporates with a constant molecular structure.
The molecules of ethanol and oxygen combine inside the flame and undergo a chemical transformation. Let's consider matter, or the atoms. The oxygen (O2) and ethanol (C2H5OH) molecules' atoms reorganise into carbon dioxide (CO2) and water (H2O). There are always the same number of atoms. A chemical equation may be used to demonstrate how the atoms are rearranged.
Energy is released as the atoms in the oxygen and ethanol are rearranged. When the high-energy C-C and C-H bonds in ethanol are swapped out for the low-energy H-O and C=O bonds in carbon dioxide and water, chemical energy is released as heat and light.
The ethanol and oxygen atoms are rearranged into carbon dioxide and water during burning. Water and carbon dioxide escape from the flame's top.
To conclude with we can say that the given reaction of combustion of ethanol. Ethanol with oxygen given carbon dioxide with water on reaction.
Learn more about Combustion of ethanol here:
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all i really know is that STP (standard temperature and pressure) represents conventional conditions established by IUPAC with T = 273.15 K, P = 1 atm . Now putting these values of temperature and pressure at STP, we can calculate easily volume occupied by 1 mol of gas and which comes out to be 22.4 L. hope this helps
I'm assuming that it is due to the breeze coming from the tides.
