Answer:
I think it is chemical change
Answer:
0.246 kg
Explanation:
There is some info missing. I think this is the original question.
<em>A chemist adds 370.0mL of a 2.25 M iron(III) bromide (FeBr₃) solution to a reaction flask. Calculate the mass in kilograms of iron(III) bromide the chemist has added to the flask. Be sure your answer has the correct number of significant digits.</em>
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We have 370.0 mL of 2.25 M iron(III) bromide (FeBr₃) solution. The moles of FeBr₃ are:
0.3700 L × 2.25 mol/L = 0.833 mol
The molar mass of iron(III) bromide is 295.56 g/mol. The mass corresponding to 0.833 moles is:
0.833 mol × 295.56 g/mol = 246 g
1 kilogram is equal to 1000 grams. Then,
246 g × (1 kg/1000 g) = 0.246 kg
Answer:
2 and 3
Explanation:
A chemical reaction is defined as the process in which two or more reactants combined together chemically and gives a different product.
A balanced chemical equation involves an equal number of atoms on the reactant and product side. A balanced chemical reaction occurs when the atoms present on the reactant side or left side of the arrow is equal to the atoms on the product side or right side of the arrow.
The process of the balanced chemical equation is based on errors and trials in which the atoms in each element is identified, the atoms are then multiplied with required numbers, the addition of coefficient in front of molecules and check the equation at last.
Hence, the correct options are "2 and 3".
Answer:
pH = 2.462.
Explanation:
Hello there!
In this case, according to the reaction between nitrous acid and potassium hydroxide:

It is possible to compute the moles of each reactant given their concentrations and volumes:

Thus, the resulting moles of nitrous acid after the reaction are:

So the resulting concentration considering the final volume (20.00mL+13.27mL) is:
![[HNO_2]=\frac{6.73x10^{-4}mol}{0.01327L+0.02000L} =0.02023M](https://tex.z-dn.net/?f=%5BHNO_2%5D%3D%5Cfrac%7B6.73x10%5E%7B-4%7Dmol%7D%7B0.01327L%2B0.02000L%7D%20%3D0.02023M)
In such a way, we can write the ionization of this weak acid to obtain:

So we can set up its equilibrium expression to obtain x as the concentration of H3O+:
![Ka=\frac{[NO_2^-][H_3O^+]}{[HNO_2]}\\\\7.1x10^{-4}=\frac{x^2}{0.02023M-x}](https://tex.z-dn.net/?f=Ka%3D%5Cfrac%7B%5BNO_2%5E-%5D%5BH_3O%5E%2B%5D%7D%7B%5BHNO_2%5D%7D%5C%5C%5C%5C7.1x10%5E%7B-4%7D%3D%5Cfrac%7Bx%5E2%7D%7B0.02023M-x%7D)
Next, by solving for the two roots of x, we get:

Whereas the correct value is 0.003451 M. Finally, we compute the resulting pH:

Best regards!
Models are used to study atoms because we can't exactly study an atom with the naked eye, Using an enlarged model of an atom easier to study because we can pin point the different characteristics of the atom.