someone answer please​

Explanation:

this explanation may help u to understand:)

Answer:

the Rhyniognatha hirsti

Explanation:

at age 400 million years old

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.

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

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

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.

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.

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 :

https://brainly.com/question/13153771

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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.

Answer:

40.4 kJ

Explanation:

Step 1: Given data

Step 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

Answer:

according to the path shown in the figure it will start decreasing then again it will start increasing when the path will be nearer to the star.

Reason is gravitation force is indirectly proportional to the distance.

So, option B. decrease then increase is correct

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!

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!

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

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!