Answer:
the Rhyniognatha hirsti
Explanation:
at age 400 million years old
It took 2.30 minutes using a current of 3.00 A to plate out all the copper from 0.300 L of a solution containing Cu2 . What was the original concentration of Cu2
Answer:
7.16 × 10⁻³ M
Explanation:
Let's consider the reduction reaction of copper during the electroplating.
Cu²⁺(aq) + 2 e⁻ ⇒ Cu(s)
We can calculate the moles of Cu²⁺ present in the solution using the following relations.
1 A = 1 C/s.1 min = 60 s.1 mole of electrons has a charge of 96486 C (Faraday's constant).1 mole of Cu²⁺ is reduced when 2 moles of electrons are gained.The moles of Cu²⁺ reduced are:
[tex]2.30 min \times \frac{60s}{1min} \times \frac{3.00C}{s} \times \frac{1mole^{-} }{96486C} \times \frac{1molCu^{2+} }{2mole^{-} } = 2.15 \times 10^{-3} molCu^{2+}[/tex]
[tex]2.15 \times 10^{-3} moles[/tex] of Cu²⁺ are in 0.300 L of solution.
[Cu²⁺] = 2.15 × 10⁻³ mol/0.300 L = 7.16 × 10⁻³ M
The value of ΔH° for the reaction below is -6535 kJ. ________ kJ of heat are released in the combustion of 16.0 g of C6H6 (l)?
2C6H6 (l) + 15O2 (g) → 12CO2 (g) + 6H2O (l)
Answer:
the value of H° is below -6535 kj. +6H2O
Explanation:
6H2O answer solved
For the given reaction, 2 moles of C₆H₆ the heat energy released is - 6535 KJ. Then, for 16 g of the compound or 0.205 moles needs 669.83 KJ of heat released in combustion.
What is combustion ?Combustion is a chemical reaction that occurs between a fuel and an oxidizing agent, typically oxygen, resulting in the release of heat, light, and various combustion products, such as carbon dioxide and water vapor.
The process of combustion involves a rapid and exothermic (heat-releasing) oxidation reaction that produces a flame, which is visible in many cases.
Here, 2 moles of the hydrocarbon releases - 6535 KJ of energy.
molar mass of C₆H₆ = 78 g/mol
then no.of moles in 16 g = 16 /78 = 0.205 moles.
then energy released by 0.205 moles = 0.205 moles × 6535 KJ /2 moles = 669.83 kJ
Therefore, the heat energy released by 16 g of the compound in combustion is 669.83 kJ.
Find more on combustion :
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38. Consider the following equilibrium:
2CO(g) + O2(g) =2CO2
Keg=4.0 x 10-10
What is the value of Key for 2CO2(g) + 2COR + O2g) ?
Answer:
[tex]Key=2.5x10^{-9}[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to calculate the equilibrium constant value for the reverse reaction:
[tex]2CO_2(g) \rightleftharpoons 2CO(g) + O_2(g)[/tex]
By knowing that the equilibrium expression is actually:
[tex]Key =\frac{[CO]^2[O_2]}{[CO_2]^2} =\frac{1}{Keg}[/tex]
Thus, we plug in and solve for the inverse of Keq to obtain Key as follows:
[tex]Key =\frac{1}{4.0x10^{-10}}\\\\Key=2.5x10^{-9}[/tex]
Regards!
In the presence of excess iodide ions, the iodine formed by reaction of iodide with NBS will react further to form triiodide ions. What does the triiodide combine with to form the blue color of the endpoint
Answer:
Starch.
Explanation:
When the triiodide combine with starch, it forms dark blue colour. Amylose in starch is responsible for the occurrence of a deep blue color when the iodine is combine with the starch. The iodine molecule goes inside of the amylose coil which makes a linear triiodide ion complex that goes into the coil of the starch that leads to an intense blue-black color in the end so we can say that starch turns the colour into blue.
If 4.00 moles of O2 occupies a volume of 5.0 L at a particular temperature and pressure, what volume will 3.00 moles of oxygen gas occupy under the same condition?
Answer: Volume occupied by 3.00 moles of oxygen gas under the same condition is 3.75 L.
Explanation:
Given: [tex]n_{1}[/tex] = 4.00 moles, [tex]V_{1}[/tex] = 5.0 L
[tex]n_{2}[/tex] = 3.00 moles, [tex]V_{2}[/tex] = ?
Formula used is as follows.
[tex]\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}[/tex]
Substitute the values into above formula as follows.
[tex]\frac{V_{1}}{n_{1}} = \frac{V_{2}}{n_{2}}\\\frac{5.0 L}{4.00 mol} = \frac{V_{2}}{3.00 mol}\\V_{2} = 3.75 L[/tex]
Thus, we can conclude that volume occupied by 3.00 moles of oxygen gas under the same condition is 3.75 L.
Calculate the amount of heat required to completely sublime 55.0 g of solid dry ice CO2 at its sublimation temperature. The heat of sublimation for carbon dioxide is 32.3 kj mol
Answer:
40.4 kJ
Explanation:
Step 1: Given data
Mass of CO₂ (m): 55.0 gHeat of sublimation of CO₂ (ΔH°sub): 32.3 kJ/molStep 2: Calculate the moles corresponding to 55.0 g of CO₂
The molar mass of CO₂ is 44.01 g/mol.
n = 55.0 g × 1 mol/44.01 g = 1.25 mol
Step 3: Calculate the heat (Q) required to sublimate 1.25 moles of CO₂
We will use the following expression.
Q = n × ΔH°sub
Q = 1.25 mol × 32.3 kJ/mol = 40.4 kJ
cuáles son las características de la luz y en qué consisten
Answer:
Cuáles son las características de la luz y en qué consisten?
Explanation:
La luz es una radiación que se propaga en forma de ondas. Las ondas que se pueden propagar en el vacío se llaman ONDAS ELECTROMAGNÉTICAS. La luz es una radiación electromagnética
Chrysanthenone is an unsaturated ketone. If Chrysanthenone has M+ = 150 and contains 2 double bond(s) and 2 ring(s); what is its molecular formula? Enter the formula in the form CH first, then all other atoms in alphabetical order; do not use subscripts. The formula is case-sensitive.
Answer:
the Molecular formula will be; C10H14O
Explanation:
Given the data in the question;
Chrysanthenone is an unsaturated ketone,
it has M+ = 150 and contains 2 double bond(s) and 2 ring(s).
molecular formula = ?
we know that ketone contain 1 oxygen and mass of oxygen is 16
so mass of the C and H remaining will be;
⇒ 150 - 16 = 134
Now we determine the number of C atoms;
⇒ 134 / 13 = 10
hydrocarbon with 10 hydrogen atom have CnH2n+2 means
⇒ ( 10 × 2 ) +2 = 22 hydrogens
But then we have 3 unsaturation meaning 6 hydrogens less and also we have ring meaning 2 more hydrogens
⇒ 22 - 6 - 2 = 14
Hence the Molecular formula will be; C10H14O
a) If we have a 4.5 L container of CH 10 gas at a temperature of 178 K and a pressure of 0.50 atm, then how many moles of CaHio do
we have?
b) How many grams of C4H1o do we have?
Answer:
a) 0.15 mol.
b) 8.95 g.
Explanation:
Hello there!
In this case, according to the given information, it is possible for us to infer this problem is solved by using the ideal gas equation:
[tex]PV=nRT[/tex]
And proceed as follows:
a) Here, we solve for the moles, n, as follows:
[tex]n=\frac{PV}{RT} \\\\n=\frac{0.50atm*4.5L}{0.08206\frac{atm*L}{mol*K}*178K} \\\\n=0.15mol[/tex]
b) for the calculation of the mass, we recall the molar mass of butane, 58.12 g/mol, to obtain:
[tex]0.15mol*\frac{58.12g}{1mol} =8.95g[/tex]
Regards!
5.96 g of ammonia reacts completely according to the following reaction:
2 NH, (g) + Co, (g) → CN,OH, (s) + H20 (1)
(a) What is the theoretical yield of urea (CN,OH,) for this reaction?
(b) If 13.74 g of urea are produced, what is the percent yield for this equation?
please show work, will give brainliest
Explanation:
this explanation may help u to understand:)
20ml of water is mixed with 40gm of fine powder. Calculate the concentration of the solution obtained.
Answer:
[tex]\%m=66.7\%[/tex]
Explanation:
Hello there!
In this case, according to the given information, it turns out possible for us to calculate the concentration of the solution obtained, by knowing 20 mL of water are the same to 20 g and therefore the mass of the solution is 40g+20g=60g.
Next, we apply the following equation to obtain the required concentration:
[tex]\%m=\frac{40g}{60g} *100\%\\\\\%m=66.7\%[/tex]
Regards!
