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2 years ago

3.

Chemistry

1 answer:

kari74 [83]2 years ago

7 0

Answer:

Explanation:

Elements in the same group of the periodic table do not have the same atomic size.

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Makovka662 [10]

Answer:

yup that's how you make friends with people on brainly

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2 years ago

Chuẩn Độ 15 ml dung dịch CH3COOH 0,2 m bằng dung dịch NaOH 0,2 m

mina [271]

Answer:

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Explanation:

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2 years ago

If element A is in Group 13 and element B is in Group 17, which ions will be formed when A and B react together?

Kobotan [32]

Answer:

A3+ and B-

Explanation:

Elements in group 13 have outermost electron configuration, ns2np1 hence they form trivalent positive ions.

Elements in group 17 have outermost electron configuration ns2np5 hence they form univalent negative ions.

This implies that, if element A is in Group 13 and element B is in Group 17, the ions formed are A3+ and B-.

8 0

2 years ago

Passing an electric current through a sample of water (H2O) can cause the water to decompose into hydrogen gas (H2) and oxygen g

Lerok [7]

The mass of water decomposed to produce 50 g oxygen has been 56.28 g. Thus, option D is correct.

The reaction for the decomposition of water has been:

$\rm 2\;H_2O\;\rightarrow\;H_2\;+\;O_2$

From the balanced equation, 2 moles of water decomposes to form 1 moles of hydrogen and 1 mole of oxygen.

The mass of oxygen produced has been 50 g. The moles of oxygen has been given by:

$\rm Moles=\dfrac{mass}{molar\;mass}$

The moles of oxygen has been:

$\rm Moles_O_2=\dfrac{50}{32}\;mol\\Moles_O_2=1.5625\;mol$

The moles of oxygen produced has been 1.5625 mol.

The moles of hydrogen decomposed has been given from the balanced chemical equation as:

$\rm 1 \;mole\;O_2=2\;mole\;H_2O\\1.5625\;mol\;O_2=1.5625\;\times\;2\;mol\;H_2O\\1.5625\;mol\;O_2=3.125\;mol\;H_2O$

The moles of hydrogen decomposes has been 3.125 mol.

The mass of hydrogen decomposed has been given by:

$\rm Mass=moles\;times\;molar\;mass\\Mass_{H_2O}=3.125\;\times\;18.01\;g\\Mass_{H_2O}=56.28\;g$

The mass of water decomposed to produce 50 g oxygen has been 56.28 g. Thus, option D is correct.

For more information about moles produced, refer to the link:

brainly.com/question/10606802

8 0

2 years ago

An unknown piece of metal weighing 95.0 g is heated to 98.0°C. It is dropped into 250.0 g of water at 23.0°C. When equilibrium i

lutik1710 [3]

Answer:

$C_{metal}=126.6\frac{J}{g\°C}$

Explanation:

Hello!

In this case, when two substances at different temperature are put in contact and an equilibrium temperature is attained, we can evidence that the heat lost by the hot substance (metal) is gained by the cold substance (water) and we can write:

$Q_{metal}=-Q_{water}$

Which can be also written as:

$m_{metal}C_{metal}(T_{EQ}-T_{metal})=-m_{water}C_{water}(T_{EQ}-T_{water})$

Thus, since we need the specific heat of the metal, we solve for it as shown below:

$C_{metal}=\frac{m_{water}C_{water}(T_{EQ}-T_{water})}{-m_{metal}(T_{EQ}-T_{metal})} \\\\C_{metal}=\frac{250.0g*4.184\frac{J}{g\°C}(29.0\°C-98.0\°C)}{95.0g(29.0\°C-23.0\°C)} \\\\C_{metal}=126.6\frac{J}{g\°C}$

Best regards.

7 0

2 years ago