All categories

3 years ago

Which of the following is a characteristic of the sun

Chemistry

2 answers:

MArishka [77]3 years ago

7 0

Answer:

it is made of gas.

Explanation:

mainly hydrogen and helium

NISA [10]3 years ago

5 0

Explanation:

It is made of gas

...............

You might be interested in

1. An atom of an elephant has atomic mass of 39 and has number of neutrons as 20 calculate protons number.

r-ruslan [8.4K]

Answer:

See Explanation

Explanation:

1) Let us recall that;

Mass number = number of protons + number of neutrons

Where;

Number of protons = ?

Number of neutrons =20

Mass number =39

Number of protons = mass number - number of neutrons

Mass of protons =39 - 20= 19 protons

2) Atomic number = 13

Number of neutrons =14

Then the mass number =13 +14 =27

The symbol of the element is 27X13

The number of protons= the number of electrons =13

The atomic number is the same as the proton number =13

5 0

3 years ago

Hydrocarbon weighing 112g is burned in air to produce 328.5 g of carbon dioxide what percent mass of carbon in the hydrocarbon

Lemur [1.5K]

Answer:

<u>80.0 %</u>

Explanation:

As per the law of conservation of mass all the mass of carbon present in the hydrocarbon weighing 112 g is present in the 328.5 g of carbon dioxide produced when the hydrocarbon was burned in air.

<u>1) Calculate the mass of carbon in 328.5 g of carbon dioxide</u>:

Chemical formula of carbon dioxide: CO₂

Molar mass of CO₂: 12.011 g/mol + 2 × 15.999 g/mol = 44.009 g/mol

Mass of C: x

x / 328.5 g CO₂ = 12.011 g C / 44.009 g/mol ⇒ x = 86.65 g C

<u>2) Calculate the percent mass of carbon:</u>

% = (mass of carbon / mass of carbon dioxide) × 100 =

= (89.65 / 112) × 100 = 80.04%

Round to three signifcant figures: 80.0%.

3 0

4 years ago

Integrated Problem 21.104 Get help answering Molecular Drawing questions Get help answering Molecular Drawing questions. When a

Zepler [3.9K]

Answer:

See explanation below

Explanation:

The malonic ester synthesis is a commonly used reaction to form several products. In this case when we have an excess of base, in presence of an alkyl halide of 4 carbons, this will promoves the formation of a ring.

This synthesis has 4 steps:

1) Enolate formation. In this step the strong base (Such as methoxyde) will substracts the more acidic atom of hydrogen in the molecule. In the malonic ester, it would be the hydrogens from carbon 2.

2) Enolate alkylation. Once the enolate has been formed in the previous step, it will become a nucleophyle, and will attack the alkyl halide to form an enolate alkyl. Then, as we have excess of base, we are going back to step 1 to substract the remaining hydrogen, and then, step 2 again so the remaining bromine leaves the molecule. In this part, it will form the ring.

3) Ester hydrolisis. When the ring is formed, it's time to do an hydrolisis of the ester, so we can convert the ester into carboxilic acids. As we have two ester,we will have two carboxilic acids.

4) Decarboxilation. Finally, a decarboxilation occurs in presence of heat to have the final product with a ring and CO2 there as final products.

See picture attached for products thislllll

3 0

3 years ago

3 Cu + 8HNO3 g 3 Cu(NO3)2 + 2 NO + 4 H2O

Ksivusya [100]

Considering the reaction stoichiometry, the amount of moles of NO that is produced when 27 moles of HNO₃ react is 6.75 moles.

<h3 /><h3>Reaction stoichiometry</h3>

The balanced reaction is:

3 Cu + 8 HNO₃ → 3 Cu(NO₃)₂ + 2 NO + 4 H₂O

By reaction stoichiometry (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of moles of each compound participate in the reaction:

Cu: 3 moles
HNO₃: 8 moles
Cu(NO₃)₂: 3 moles
NO: 2 moles
H₂O: 4 moles

<h3>Amount of moles of NO produced</h3>

It is possible to determine the the amount of moles of NO produced by a rule of three: if by stoichiometry 8 moles of HNO₃ produce 2 moles of NO, if 27 moles of HNO₃ react how many moles of NO will be formed?

$amount of moles of NO=\frac{27 moles of HNO_{3} x 2 moles of NO}{8 moles of HNO_{3}}$