A bicycle rusting after it is left in the rain is an example of a chemical reaction because it involves oxidation (Option d).
<h3>What is a chemical reaction?</h3>
A chemical reaction can be defined as a phenomenon in which one or more substances called reactants react to form one or more different compounds, which are known as products.
A chemical reaction may include an enzyme that works to increase the seed of the reaction in normal conditions by lowering the activation energy of the reaction.
Therefore, we can conclude that a chemical reaction such as oxidation in a bicycle is a process where reactants combine or break down to form the products of such reaction.
Complete question:
Which of the following situations contains an example of a chemical reaction?
a. Ice forming after water is placed in a freezer
b. Watercolor paint drying on paper
c. a sugar cube dissolving in a glass of water
d. a bicycle rusting after it is left in the rain
Learn more about chemical reactions here:
brainly.com/question/11231920
#SPJ1
Answer:
Fluorine is the most corrosive element in the periodic table.
Explanation:
Unfortunately, you failed to include the table 1 from which the molar heat capacity of aluminum could have been obtained. However, as a general rule, the heat needed to raise the temperature of a certain substance by certain degrees is calculated through the equation,
H = mcpdT
where H is heat, m is mass, cp is specific heat capacity, and dT is change in temperature. From a reliable source, cp for aluminum is equal to 0.215 cal/g°C. Substituting this to the equation,
H = (260.5 g)(0.215 cal/g°C)(125°C - 0)
H = 7000.94 cal
Answer:
a) [H₃O⁺] = 1.8x10⁻⁵ M
b) pH = 4.75
c) % rxn = 3.5x10⁻³ %
Explanation:
a) The dissociation reaction of HCN is:
HCN(aq) + H₂O(l) ⇄ H₃O⁺(aq) + CN⁻(aq)
0.5 M - x x x
The dissociation constant from the above reactions is given by:
![Ka = \frac{[H_{3}O^{+}][CN^{-}]}{[HCN]} = 6.17 \cdot 10^{-10}](https://tex.z-dn.net/?f=Ka%20%3D%20%5Cfrac%7B%5BH_%7B3%7DO%5E%7B%2B%7D%5D%5BCN%5E%7B-%7D%5D%7D%7B%5BHCN%5D%7D%20%3D%206.17%20%5Ccdot%2010%5E%7B-10%7D)
By solving the above quadratic equation we have:
x = 1.75x10⁻⁵ M = 1.8x10⁻⁵ M = [H₃O⁺] = [CN⁻]
Hence, the [H₃O⁺] is 1.8x10⁻⁵ M.
b) The pH is equal to:
![pH = -log[H_{3}O^{+}] = -log(1.75 \cdot 10^{-5} M) = 4.75](https://tex.z-dn.net/?f=pH%20%3D%20-log%5BH_%7B3%7DO%5E%7B%2B%7D%5D%20%3D%20-log%281.75%20%5Ccdot%2010%5E%7B-5%7D%20M%29%20%3D%204.75)
Then, the pH of the HCN solution is 4.75.
c) The % reaction is the % ionization:
![\% = \frac{x}{[HCN]} \times 100](https://tex.z-dn.net/?f=%20%5C%25%20%3D%20%5Cfrac%7Bx%7D%7B%5BHCN%5D%7D%20%5Ctimes%20100%20)
Therefore, the % reaction or % ionization is 3.5x10⁻³ %.
I hope it helps you!
The % yield if 500 g of sulfur trioxide reacted with excess water to produce 575 g of sulfuric acid is calculated using the below formula
% yield = actual yield/ theoretical yield x100
actual yield =575 grams
to calculate theoretical yield
find the moles of SO3 used =mass/molar mass
= 500g/ 80 g/mol =6.25 moles
SO3+H2O=H2SO4
by use of mole ratio of SO3 : H2SO4 which is 1:1 the moles of H2SO4 is also= 6.25 moles
the theoretical yield of H2SO4 is therefore = moles /molar mass
= 6.25 x98= 612.5 grams
%yield is therefore= 575 g/612 g x100= 93.9 %
