what element is this

Answer:

0.38

Explanation:

Molar mass of thiophene= 84g/mol

Mass of thiophene = 37g

Number of moles= 37/84= 0.44 moles

Molar mass of heptane= 100 g/mol

Mass of heptane = 72g

Number of moles = 72/100= 0.72 moles

Total number of moles= 0.44 + 0.72= 1.16 moles

mole fraction of thiophene = 0.44/1.16= 0.38

Answer:

Dissolves a chemical sample well at high temperatures.

Does not dissolve a chemical sample well at low temperatures.

Explanation:

Recrystallization is a purification technique that involves mixing of an impure solid compound with a hot solvent leading to a saturated solution. As this solution cools, the compound to be purified becomes less soluble in the solvent, and pure crystals appear from the solution as the solution cools.

A good recrystallization solvent should

invertebrate is a animal that does not have a back bone but may have a exoskeleton examples could be earthworm, jellyfish, snail and a spider because it has a exoskeleton a hard outer shell hope this helps

Vertebrates have a back bone like sea turtles , fish ,foxes and humans.

Answer:

there's just a lot of drama around grumpy trumpy's StOlEN eLecTiOn which are all just fake claims. all his hardcore followers are brainwashed into believing anything he says, so people (especially people who are inside the capitol) fear that trump's followers might incite violence AGAIN even after they broke into the Capitol on the 6th.

That's why they have the National Guard and thousands of people to keep the building secure during Biden's Inauguration.

hope this helps!

Answer:

Gallium

Explanation:

Answer:

Gallium

Explanation:

Answer: it would stop producers from producing food.

Explanation: why? Without the action of the producers to turn sunlight into food, the producers would die, and consumers that rely on them would lose their food source and die too.

Answer:

It would stop producers from producing food

Explanation:

Producers would die, and if producers died, consumers would die too.

Hope this helps

Answer:

[tex]MM_{mixture}=9.68g/mol[/tex]

Explanation:

Hello!

In this case, since the molar mass of gaseous mixtures can be determined via a weighted average containing the molar mass of each gas and the mole fraction (mole percent divided by 100) as shown below:

[tex]MM_{mixture}=x_{CO_2}M_{CO_2}+x_{N_2}M_{N_2}+x_{He}M_{He}[/tex]

Now, we plug in to obtain:

[tex]MM_{mixture}=0.11*44g/mol+0.053*28+0.84*4\\\\MM_{mixture}=9.68g/mol[/tex]

Best regards!

Answer:

- P in PBr3 is +3.

- N in N2 is 0.

- As in H3AsO4 is +5.

Explanation:

Hello!

In this case, since the determination of the oxidation states is performed by using the well-known charge balances, we can proceed as shown below:

- P in PBr3: Here, bromide ions have an oxidation state of -1, so we follow:

[tex]P^xBr_3^-\\\\x-3=0\\\\x=+3[/tex]

Thus, the oxidation state is +3.

- N in N2: Here, since nitrogen is bonding with nitrogen and it is neutral, we infer its oxidation state is 0.

- As in H3AsO4: Here, oxygen is -2 and hydrogen +1, so we follow:

[tex]H_3^+As^xO_4^{-2}\\\\3+x-8=0\\\\x=8-3\\\\x=5[/tex]

Thus, the oxidation state is +5.

Best regards!

Answer:

It does not matter where the sample of water came from or how it was prepared. Its composition, like that of every other compound, is fixed.

Answer:

Molar mass of CaO

(40 + 16)g

= 56g

hope it helps you

Answer:

348.9 mL of the 60% solution and 251.1 mL of the 15% solution.

Explanation:

First, we calculate how many mililiters of pure carbonic acid are there in 650 mL of a 38% solution:

Then we can express the sum of both initial solutions as:

for the volume of carbonic acid; and

For the volume of the solutions.

We now have a system of two equations and two unknowns (x is the volume of the 60% solution and y is the volume of the 15% solution).

We express x in terms of y in equation 2):

And replace x in equation 1):

Finally we calculate x using equation 2):

Since, the options have not been given the question is incomplete.

What is Darwin's name for species that do not appear to have changed for millions of years?

a.

Dinosaurs

b.

Living fossils

c.

Old souls

d.

Ancient moderns

Answer: b. Living fossil

Explanation:

In 1859 Charles Darwin proposed the term living fossil, that means a species or group of species that had not changed in terms of evolutionary context thus can be useful in tracing the extinct or previously existing forms of life. The examples of the living fossils are horseshoe crabs, ginkgo (Conifers) and tuatara. These group of animals were existed unchanged in the Ordovician, Permian, and Triassic periods respectively with few surviving species.

Answer:

the answer is living fossils so it would be b

Explanation:

how do i know i took the test

Answer:

D

Explanation:

it's a star it has gas and makes it own light

Answer:

wouldnt they still have the same density?

Explanation:

for example, the density of iron is 7.874 g/cm^3 no matter how big the piece is. I hope this helps.

Answer:

a. 1-fluoro-3,3,4-trimethyl-pentane.

b. 1-iodo-3-ethyl-2-methyl-hexane.

c. 1,3-dichloro-5-dimethyl-hexane.

d. 1-bromo-3-methyl-cyclopentane.

Explanation:

Hello!

In this case, according to the IUPAC rules for the listed alkyl halides, we first need to name the halogens (considering periodic order) then alkyl radicals and finally the parent chain; thus, the names are given below:

a. 1-fluoro-3,3,4-trimethyl-pentane.

b. 1-iodo-3-ethyl-2-methyl-hexane.

c. 1,3-dichloro-5-dimethyl-hexane.

d. 1-bromo-3-methyl-cyclopentane.

e. 5-chloro-1-bromo-1,1,5-trimethyl-pentane (radicals are not clear).

Best regards!

Answer:

Strontium is the second element placed in the 5th period

Hope this will help you if not so advance sorry :)

Answer:

Explanation:

From the combustion of carbon, the reactions occurring in limited oxygen conditions are:

[tex]C(graphite) + \dfrac{1}{2}O_{2(g)} \to CO_{(g)}[/tex]  

[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex]  

If it occurs in excess, then any leftover CO changes to CO2. i.e.

[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex]   ---- (1)

[tex]CO_{(g)} + \dfrac{1}{2}O_{(g)} \to CO_{2(g)}[/tex]          ----- (2)

From (1), the enthalpy change is:

[tex]\Delta H_{rxn1} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{f C(graphite)}+ \Delta H^0_{fCO_2(g)}[/tex]

[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol -(0+0)[/tex]

[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol[/tex]

From (2), the enthalpy change is:

[tex]\Delta_{rxn2} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{fCO(g)} + \dfrac{1}{2} \Delta H^0_{fO_2(g)})[/tex]

[tex]\Delta_{rxn2} = -393.5 \ kJ/mol -(-110.5 + \dfrac{1}{2}(0))[/tex]

[tex]\Delta_{rxn2} = -283.0 \ kJ/mol[/tex]

Subtracting (2) from (1), we get:

[tex]C(graphite) + O_{2(g)} \to CO_{2(g)} \ \ \ \Delta H_{rxn} = -393.5 \ kJ/mol}[/tex]

[tex]CO_{(g)} + \dfrac{1}{2} O_2(g) \to CO_{2(g)}} \ \ \ \Delta H _{rxn2} = -283.0 \ kJ/mol[/tex]

[tex]C(graphite) + O_{2(g)} \to CO (g) + \dfrac{1}{2}O_{2(g)} \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]

[tex]C(graphite) + \dfrac{1}{2} O_{2(g)} \to CO (g) \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]

The enthalpy change ΔH of the reaction = -110.5 kJ/mol

Answer: 1.695x10^24 atoms

Explanation: 0.938 moles CO2 = 0.938xavogadro number molecules CO2, so number of atoms = 3x0.938x6.02214076x10^23 = 1.695x10^24

Answer:

The First Battle of Panipat was fought between the invading forces of Babur and the Lodi Empire, which took place on 21 April 1526 in North India. It marked the beginning of the Mughal Empire. This was one of the earliest battles involving gunpowderfirearms and field artillery.

For you to write an essay on  Panipat first bring into view

Then write a brief story using this format.

In writing this essay, you must consider the structure and content of the essay or short note

For structure kick off with

In conclusion, for the content of the short note you can consider this,

Panipat fought its first battle on 21 April 1526 in the North of India, This battle was fought between the invading powers of Babur and the Lodi Empire.

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Answer:

[tex]C_3H_6[/tex]

Explanation:

Hello!

In this case, since the empirical formula is the smallest representation of the molecular formula, it is known that the times in which the empirical formula is into the molecular formula is a whole number and is computed by dividing the molar mass of the molecular formula by that of the empirical formula as shown below:

[tex]\frac{42.08g/mol}{12.01+1.01x2}= \frac{42.08g/mol}{14.03g/mol}=3[/tex]

Thus, the molecular formula times the empirical formula by 3 to obtain:

[tex]C_3H_6[/tex]

Regards!

Answer:

B. Irreversible

Explanation:

Answer: C  Reversible

Explanation:

Founder's Education Quiz

Answer:

V = 11.2L are produced

Explanation:

... Sample of 27g of pure aluminium, 3added to 333 mL of 3.0 M HCl..

Based on the chemical reaction:

2Al(s) + 6HCl(aq) → 2AlC₃(aq) + 3H₂(g)

Where 3 moles of hydrogen are produced when 6 moles of hydrochloric acid reacts with 2 moles of Al.

To solve this question, we need to determine limiting reactant converting each reactant to moles. With limiting reactant and the chemical reaction we can find moles of hydrogen and its volume at STP (T=273.15K; P=1atm), thus:

Moles Al-Molar mass: 26.98g/mol-:

27g * (1mol / 26.98g) = 1mol of Al

Moles HCl:

333mL = 0.333L * (3mol/L) = 1mol HCl

For a complete reaction of 1 mole of HCl are required:

1mol HCl * (2mol Al / 6mol HCl) = 0.333 moles of Al. As there is 1 mole of Al, Al is in excess and HCl is limiting reactant.

Moles of Hydrogen produced are:

1mol HCl * (3 moles H₂ / 6 mol HCl) = 0.5moles H₂ are produced.

Using ideal gas law:

PV = nRT

V = nRT/P

Where V is volume

n are moles: 0.5mol

R is gas constant: 0.082atmL/molK

T is absolute temperature: 273.15K

P is pressure: 1atm.

Solving for V:

V = 0.5mol*0.082atmL/molK*273.15K / 1atm

Answer:

B. Cell Type

Explanation:

that is the answer i believe

Answer:

option b- cell type

Explanation:

almost absolutely positive

To solve this we must be knowing each and every concept related to force. Therefore, the  objects motion will be towards downward with a force of 5 N.

A force is an outside entity that has the power to alter a body's state of rest or motion. It has a direction and a magnitude. The point where forces are applied is determined by the the force's direction as well as the application of the force.

Newton and dyne units are used to measure the force exerted on an item. When using the centimeter kilogram second system of units, force is measured in dynes (CGS unit). In the common international system of units, it is denoted by the letter Newton (N) (SI unit).

upward force=5 N

downward force= 10 N

total force acting on body=downward force-upward force

                                          = 10 N - 5 N

                                          =5 N downward force

The  objects motion will be towards downward with a force of 5 N.

Therefore, the  objects motion will be towards downward with a force of 5 N.

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Answer:

By bonding due to the attractive forces

Answer:

17.031 g/mol

Explanation: