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Elan Coil [88]
4 years ago
11

What is the percent by mass of oxygen in al2o3 ?

Chemistry
1 answer:
Snezhnost [94]4 years ago
4 0
mr oxygen= 16. 16 x 3= 48
mr Al2O3= 27 + 27 + 48= 102

(48/102) X 100%= 47.05% oxygen
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(part 1 of 3) Copper reacts with silver nitrate through a single replacement. If 1.29 g of silver are produced from the reaction
ale4655 [162]

Answer:

See explanation.

Explanation:

Hello there!

In this case, according to the described chemical reaction, we first write the corresponding equation to obtain:

Cu+2AgNO_3\rightarrow 2Ag+Cu(NO_3)_2

Thus, we proceed as follows:

Part 1 of 3: here, since the molar mass of silver and copper (II) nitrate are 107.87 and 187.55 g/mol respectively, and the mole ratio of the former to the latter is 2:1, we can set up the following stoichiometric expression:

m_{Cu(NO_3)_2}=1.29gAg*\frac{1molAg}{107.87gAg}*\frac{1molCu(NO_3)_2}{2molAg}*\frac{187.55gCu(NO_3)_2}{1molCu(NO_3)_2}   \\\\m_{Cu(NO_3)_2}=1.12gCu(NO_3)_2

Part 2 of 3: here, the molar mass of copper is 63.55 g/mol and the mole ratio of silver to copper is 2:1, the mass of the former that was used to start the reaction was:

m_{Cu}=1.29gAg*\frac{1molAg}{107.87gAg}*\frac{1molCu}{2molAg}*\frac{63.55gCu)_2}{1molCu}   \\\\m_{Cu}=0.380gCu

Part 3 of 3: here, the molar mass of silver nitrate is 169.87 g/mol and their mole ratio 2:2, thus, the mass of initial silver nitrate is:

m_{AgNO_3}=1.29gAg*\frac{1molAg}{107.87gAg}*\frac{2molAgNO_3}{2molAg}*\frac{169.87gAgNO_3}{1molAgNO_3}   \\\\m_{AgNO_3}=2.03gAgNO_3

Best regards!

5 0
3 years ago
Suppose that Biuret reagent turns purple when it is added to an unknown substance. What can you conclude about the substance?
Oksi-84 [34.3K]

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the unknown substance is a protein

Explanation:

The biuret test is one of the tests for proteins. It  can be used to  detect peptide linkages. The biuret test is carried out in an alkaline solution. A coordination complex is formed  leading to the appearance of a  violet color.

Summarily, the biuret method is a colorimetric technique used to test for proteins and peptides.  It involves the formation of  a purple (violet) complex of Copper salts in alkaline solution.

Hence when the biuret reagent is added to an unknown substance and it turns purple, the unknown substance is a protein

6 0
3 years ago
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s2008m [1.1K]

Answer:

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Explanation:

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4 years ago
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Over [174]

Answer:

the pressure would increase

Explanation:

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There are exceptions, such as ammonia NH3, which acts as a base but does not produce OH- ions. There are three definitions of acids and bases (Arrhenius, Bronsted-Lowry, and Lewis) and each one looks at acid/base characteristics differently. OH- donation is the Arrhenius definition.
4 0
4 years ago
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