The element is Si (Silicon)
More about Silicon
silicon (Si), a nonmetallic chemical element in the carbon family (Group 14 [IVa] of the periodic table). Silicon makes up 27.7 percent of Earth’s crust; it is the second most abundant element in the crust, being surpassed only by oxygen.
Silicon is a naturally occurring mineral. It's the second-most abundant element on earth after oxygen. Food sources include water, fruits, and vegetables.
Silicon supplements are sometimes used as medicine. It's not clear if silicon has a function in the human body. But there's some evidence it might have a role in forming bone and collagen.
People use silicon for weak bones (osteoporosis), aging skin, and many other conditions, but there is no good scientific evidence to support most of these uses.
Do not confuse silicon with silicone. Silicone is a group of materials resembling plastic that are used to make medical devices.
To learn more about Silicone
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Answer:
C
Explanation:
When the Kb is given, the Henderson-Hasselbalch equation can be used to calculate the pOH of a buffer solution:
pOH = pKb + log ([A⁻] / [HA]) = -log(Kb) + log ([BH+] / [B])
Here, moles can be used in place of the concentration since the pairs listed are both dissolved in 5L, which cancel due to the fraction in the logarithm.
a) pOH = -log(1.8 x 10⁻⁵) + log(1.5/1.0) = 4.92
pH = 14 - pOH = 14 - 4.92 = 9.08
b) pOH = -log(1.8 x 10⁻⁵) + log(1.0/1.5) = 4.57
pH = 14 - pOH = 14 - 4.57 = 9.43
c) pOH = -log(1.7 x 10⁻⁹) + log(1.5/1.0) = 8.95
pH = 14 - pOH = 14 - 8.95 = 5.05
d) pOH = -log(1.7 x 10⁻⁹) + log(1.0/1.5) = 8.59
pH = 14 - pOH = 14 - = 5.41
<u>Answer:</u> The balanced chemical equation for the combustion of liquid ethanol is written below.
<u>Explanation:</u>
Combustion reactions are defined as the reactions in which a hydrocarbon reacts with oxygen gas to produce carbon dioxide and water. Heat is released during these reactions.
A balanced chemical equation is defined as the equation in which total number of individual atoms on the reactant side is equal to the total number of individual atoms on product side.
The balanced chemical equation for the combustion of liquid ethanol follows:
![C_2H_5OH(l)+3O_2(g)\rightarrow 2CO_2(g)+3H_2O(g)](https://tex.z-dn.net/?f=C_2H_5OH%28l%29%2B3O_2%28g%29%5Crightarrow%202CO_2%28g%29%2B3H_2O%28g%29)
By Stoichiometry of the reaction:
1 mole of liquid ethanol reacts with 3 moles of oxygen gas to produce 2 moles of carbon dioxide gas and 3 moles of water vapor.
Hence, the balanced chemical equation for the combustion of liquid ethanol is written above.
2 C3H6 + 2 NH3 + 3 O2 -> 2 C3H3N + 6 H2O
Molar masses
C3H6: 42.08 g/mol
NH3: 17.03 g/mol
O2: 32 g/mol
CH3H3N: 53.06 g/mol
H2O: 18 g/mol
# of moles
C3H6: 15.0 g / [42.08 g/mol] = 0.356 mol
NH3: 5.00 g / [17.03 g/mol] = 0.294 mol
O2: 10.0 g / [32 g/mol] = 0.313 mol
Now wee need to find the limitant reactant
The theoretical proportion is 2:2:3, equivalent to 1:1:1.5
The proportion ot the given gases is 0.356 : 0.294 : 0.313, dividing by 0.294 that is equivalent to: 1.2 : 1 : 1.06, where you see that O2 is below the theoretical proportion and it is the limitant reactant.
Now, from the equation you have 3 mol of O2 produces 2 mol of acrylonitrile (C3H3N)
Then you will obtain 0.313 * 2/3 = 0.209 mol acrylonitrile
The mass is 0.209mol * 53.06 g/mol = 11.07 g acrylonitrile
Answer: 11.07 g
Explanation:
First determine the weight of the density bottle(A1) when it's empty.
Then fill it with the liquid you want to determine the density.
Then determine the weight of the bottle with the liquid(A2).
Then the weight of the liquid is equal to (A2 - A1)
You already know the volume of the bottle.
Apply them to density = weight/volume
Make sure to mention the temperature you measured it because density varies from one temperature to another.