All categories

3 years ago

100 POINTS!!!!

Chemistry

2 answers:

zloy xaker [14]3 years ago

8 0

Answer:

The answer is C

Explanation:

SOVA2 [1]3 years ago

5 0

Answer:

Explanation:

solid snow melts; liquid water evaporates; gaseous water vapor condenses; water freezes; precipitation of frozen water (snow) back to Earth

only cycle that makes sense

You might be interested in

21. What is happening in terms of energy and attractive/repulsive forces when atoms come together and

muminat

Answer:

So A covalent bond consists of the mutual sharing of one or more pairs of electrons between two atoms. These electrons are simultaneously attracted by the two atomic nuclei. A covalent bond forms when the difference between the electronegativities of two atoms is too small for an electron transfer to occur to form ions.

Explanation:

words to know: covalent bond, electronegativities, and simultaneously

Covalent Bond: A chemical bond formed when electrons are shared between two atoms. Usually each atom contributes one electron to form a pair of electrons that are shared by both atoms.

Electronegativities: the degree to which an element tends to gain electrons and form negative ions in chemical reactions.

Simultaneously: at the same time.

hope this helps!

6 0

2 years ago

Carbon-14 is best used to find the age of:

Svetradugi [14.3K]

Answer:

anciet fossils

Explanation:

Radiocarbon dating involves determining the age of an ancient fossil or specimen by measuring its carbon-14 content. Carbon-14, or radiocarbon, is a naturally occurring radioactive isotope that forms when cosmic rays in the upper atmosphere strike nitrogen molecules, which then oxidize to become carbon dioxide.

5 0

2 years ago

In the reaction H2CO3 (aq) + 2NH3 (aq) = 2NH4^+ (aq) + CO3 2- (aq), how many electrons are transferred?

aalyn [17]

The electrons are transferred when the reaction is redox reaction. It means that there must be reduction and oxidation.

The given equation is

$H_{2}CO_{3} (aq)+2NH_{3} (aq)=2NH_{4}^{+}(aq)+CO_{3}^{-2}(aq)$

The oxidation number of each element remains the same before and after the reaction.

H = +1

C: +4

O: -2

N: -3

Thus this is simple acid base reaction and not redox

There is transfer of proton from bicarbonate to ammonia

this is not a redox reaction

3 0

3 years ago

Many computer chips are manufactured from silicon, which occurs in nature as SiO2. When SiO2 is heated to melting, it reacts wit

Mariulka [41]

Answer:

(a): The theoretical yield of silicon is 72.33 kg.

(b): The percent yield of the reaction is 91.25 %.

Explanation:

Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.

Excess reagent is defined as the reagent which is left behind after the completion of the reaction.

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

For $SiO_2$ :

Given mass = 155.0 kg = 155000 g (Conversion factor: 1 kg = 1000 g)

Molar mass = 60 g/mol

Putting values in equation 1:

$\text{Moles of }SiO_2=\frac{155000g}{60g/mol}=2583.3mol$

For carbon:

Given mass = 78.2 kg = 78200 g

Molar mass = 12 g/mol

Putting values in equation 1:

$\text{Moles of carbon}=\frac{78200g}{12g/mol}=6516.67mol$

The chemical equation for the reaction of silicon dioxide and carbon follows:

$SiO_2+2C\rightarrow Si+2CO$

By stoichiometry of the reaction:

1 mole of $SiO_2$ reacts with 2 moles of carbon

So, 2583.3 moles of $SiO_2$ will react with = $\frac{2}{1}\times 2583.3=5166.4mol$ of carbon

As the given amount of carbon is more than the required amount. Thus, it is present in excess and is considered as an excess reagent.

Thus, $SiO_2$ is considered a limiting reagent because it limits the formation of the product.

For (a):

By stoichiometry of the reaction:

1 mole of $SiO_2$ produces 1 mole of silicon

So, 2583.3 moles of $SiO_2$ will produce = $\frac{1}{1}\times 2583.3=2583.3mol$ of silicon

Since the molar mass of silicon = 28 g/mol

Putting values in equation 1:

$\text{Mass of Si}=2583.3mol\times 28g/mol=72332.4g=72.33 kg$

Hence, the theoretical yield of silicon is 72.33 kg.

For (b):

The percent yield of a reaction is calculated by using an equation:

$\% \text{yield}=\frac{\text{Measured value}}{\text{Theoretical value}}\times 100$ ......(2)

Given values:

Measured value of silicon = 66.0 kg

Theoretical value of silicon = 72.33 kg

Putting values in equation 1:

$\% \text{yield}=\frac{66.0kg}{72.33kg}\times 100\\\\\% \text{yield}=91.25 \%$

Hence, the percent yield of the reaction is 91.25 %.

3 0

3 years ago

A ________ has wavy or wrinkled foliations. These rocks usually have a pseudo-metallic luster from the abundance of mica.

zhuklara [117]

The answer is B hope it helps pls mark branliest

7 0

2 years ago