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3 years ago

Please help me and thank you

Chemistry

1 answer:

Alex17521 [72]3 years ago

6 0

Answer:

The physical and chemical properties of the product do not match the properties of the reactant.

Explanation:

Chemical change:

The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.

These changes are irreversible

These changes occur due to chemical reactions

These may not be observed with naked eye

Example:

Combustion of fuel or wood: that oil or wood convert into energy, CO2 and ash in case of wood

Boiling of egg: that change the chemical composition of protein in the egg .

The reaction of Hydrogen and oxygen:

H 2 (g) + O 2 (g) -------------------------------------> 2H 2O (l)

The reaction between sugar and oxygen form a product which is different from the reactant that's why it indicate the occurrence of chemical reaction.

While in case of physical changes just state of matter are changed. Properties remain same.

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Given the following chemical equation, if 50.1 grams of silicon dioxide is heated with excess carbon and 32.3 grams of silicon c

aivan3 [116]

Answer:

97%.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is given below:

SiO2 (s) + 3C (s) —> SiC(s) + 2CO(g)

Next, we shall determine the mass of SO2 that reacted and the mass of SiC produced from the balanced equation. This is illustrated below:

Molar mass of SiO2 = 28 + (16x2) = 60 g/mol

Mass of SO2 from the balanced equation = 1 x 60 = 60 g

Molar mass of SiC = 28 + 12 = 40 g/mol

Mass of SiC from the balanced equation = 1 x 40 = 40 g.

From the balanced equation above,

60 g of SiO2 reacted to produce 40 g of SiC.

Next, we shall determine the theoretical yield of SiC. This can be obtained as follow:

From the balanced equation above,

60 g of SiO2 reacted to produce 40 g of SiC.

Therefore, 50.1 g of SiO2 will react to produce = (50.1 x 40)/60 = 33.4 g of SiC.

Therefore, the theoretical yield of SiC is 33.4 g

Finally, we shall determine the percentage yield of SiC as follow:

Actual yield of SiC = 32.3 g

Theoretical yield of SiC = 33.4 g

Percentage yield =?

Percentage yield = Actual yield /Theoretical yield x 100

Percentage yield = 32.3/33.4 x 100

Percentage yield = 96.7 ≈ 97%

Therefore, the percentage yield of the reaction is 97%.

3 0

3 years ago

Two different bromide solutions are mixed with each other: Solution 1 is an aqueous solution of 4.85 g aluminum bromidein 150. m

erma4kov [3.2K]

Answer:

M=0.380 M.

Explanation:

Hello there!

In this case, given those two solutions of aluminum bromide and zinc bromide, it is firstly necessary to compute the moles of bromide ions in each solution as shown below:

$n_{Br^-}^{in\ AlBr_3}=4.85 gAlBr_3*\frac{1molAlBr_3}{266.69gAlBr_3}*\frac{3molBr^-}{1molAlBr_3} =0.05456molBr^-\\\\n_{Br^-}^{in\ ZnBr_2}=7.75gZnBr_2*\frac{1molZnBr_2}{225.22gZnBr_2}*\frac{2molBr^-}{1molZnBr_2} =0.06882molBr^-$

Now, we compute the total moles of bromide:

$n_{Br^-}=0.05456mol+0.06882mol\\\\n_{Br^-}=0.12338mol$

Then, the total volume in liters:

$150mL+175mL=325mL*\frac{1L}{1000mL} \\\\=0.325L$

Therefore, the concentration of total bromide is:

$M=\frac{0.12338mol}{0.325L}\\\\M=0.380M$

Best regards!

8 0

3 years ago

Alcohol and water have different melting points. which method would you use to separate them?

yuradex [85]

The process of separating alcohol from water can be done in several different ways. The most familiar method is through heating the blended liquid. Since alcohol has a lower boiling temperature than water, it will rapidly become steam. It can then be condensed into a separate container. You can also freeze the alcoholic mixture, which allows for partial removal of the nonalcoholic components; what remains will be more rich in alcohol. Use ordinary table salt to separate isopropyl alcohol from water. The result will be a condensed isopropyl alcohol, not a drinking alcohol.

4 0

3 years ago

Help! What did I do wrong??

iogann1982 [59]

The molecules of hydrogen gas that are formed is when 48.7 g of sodium are added to water is 6.375 x 10²³ molecules

<u><em>calculation</em></u>

2 Na +2H₂O → 2 NaOH +H₂

Step 1: find the moles of sodium (Na)

moles =mass÷ molar mass

from periodic table the molar mass of Na = 23 g/mol

moles= 48.7 g÷ 23 g/mol =2.117 moles

Step 2:use the mole ratio to determine the moles of H₂

from given equation Na:H₂ is 2:1

therefore the moles of H₂ = 2.117 moles x 1/2=1.059 moles

Step 3: find the molecules of H₂ using the Avogadro's law

According to Avogadro's law 1 mole = 6.02 x 10²³ molecules

1.059 moles = ? molecules

by cross multiplication

= [(1.059 moles x 6.02 x10²³ molecules) / 1 mole] =6.375 x 10²³ molecules

4 0

3 years ago

Can someone tell me what to write for here ?

professor190 [17]

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5 0

3 years ago