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4 years ago

If 75 kJ of heat is transferred to 1200 g liquid water at 36°C, what would the

Chemistry

1 answer:

Aloiza [94]4 years ago

7 0

Answer:

50.9° (corrected to 3 significant figures)

Explanation:

Energy(J) = mass(kg) x specific heat capacity x temperature change

(E = mcΔT)

Let the new temperature be T.

75000 = (1.2 )(4186)(T-36)

14.930 = T -36

T = 50.9°

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Assume that the complete combustion of one mole of glucose, a monosaccharide, to carbon dioxide and water liberates 2870 kJ2870

Lubov Fominskaja [6]

Answer:

number of moles of the compound $\approx$ 53 mole

Explanation:

Given that:

The total energy liberated = - 2870 kJ ( here , the negative sign typical implies the release of energy due to the combustion reaction)

The equation of the reaction can be represented as:

$\mathbf{C_6H_{12}O_6_{(s)} + 6O_{2(g)} \to 6CO_{2(g)}+6H_2O_{(l)}}$

The energy needed to synthesize 1 mole of compound X = - 54.1 kJ.mol

Thus;

The total energy = numbers of moles of compound × Energy needed to synthesize 1 mole of compound X

Making the numbers of moles of the compound the subject; we have;

numbers of moles of compound = $numbers \ of \ moles \ of \ compound = \dfrac{total \ energy }{Energy \ needed \ to \ synthesize \ 1 \ mole \ of \ compound \ X}$ $numbers \ of \ moles \ of \ compound = \dfrac{-2870 \ kJ }{-54.1 \ kJ/mol}$

number of moles of the compound = 53.04990 mole

number of moles of the compound $\approx$ 53 mole to two significant figure

7 0

4 years ago

Name one way you benefit from each of the following states of matter

ira [324]

There are so many different answers to this, so I don't know if you're looking for specifics but this is my personal answer.

Liquid- for drinking

Gases- you inhale gases

Solid- they support your weight, such as chairs

6 0

3 years ago

HURRY PLEASE

katrin2010 [14]

Answers:

Question 1:

The diagram for gallium will have flat, horizontal lines at 30 and 2204 °C.

Questoin 2:

The diagram for methane will have a diagonal line representing the liquid phase between -183°C and -162°C.

Question 3:

For gold, the boiling point corresponds to the y-value at 2856 °C of the top horizontal line

Question 4.

For nitrogen, the line at -210°C will be flat, which represents the change from a solid to a liquid

Explanations:

Question 1:

The diagram for gallium will have flat, horizontal lines at 30 and 2204 °C.

The table shows that the melting point of gallium is 30°C and its boiling point is 2204°C.

Melting point is the temperature at which the substace changes its state from solid to liquid. During that change, the temperature of the substance does not change, because the heat supplied is used to accomplish the phase change. So, the temperature is constant and that means that portion of the diagram is flat.

The same is valid during boiling: the temperature remains constant while the substance is passing from liquid to gas at the boiling point.

Questoin 2:

The diagram for methane will have a diagonal line representing the liquid phase between -183°C and -162°C.

Between the melting (-183°C) and boiling (-162°C) points of methane, its temperature will increase more or less linearly, which is represented with a diagonal (slant) line between those points. During this interval the heat is used to increase the temperature and no phase of change happens.

Question 3:

For gold, the boiling point corresponds to the y-value at 2856 °C of the top horizontal line

The table shows that the boiling point of gold is 2,856°C.

In a temperature-vs.-time diagram the temperature is represented on the vertical axis (y-value) and the time is represented on the horizontal axis.

Since, the temperature of the substance does not change during boiling, the line during the time that this change of phase is happening is flat. And since this temperatue is higher than the melting temperature, this is the top horizontal line in the diagram.

Question 4.

For nitrogen, the line at -210°C will be flat, which represents the change from a solid to a liquid

The table shows that the melting point of nitrogen is -210°C, that means that the temperature will remain constant at -210°C while the substance is absorbing heat to pass from solid to liquid.

In conclusion, you must remember that all the phase changes, melting (from solid to liquid), freezing (from liquid to solid), boilng (from liquid to gas), and condensing (from gas to liquid) happens at constant temperature, and so the temperature - vs. - time diagrams show flat lines (constant y-values) during those intervals of time.

4 0

3 years ago

Read 2 more answers

If 45.0 mL of 6.00M HCl is added to 130 mL of H2O, Determine the molarity of the final solution. (show work)

Ivahew [28]

2.07 M is the molarity of the final solution if 45.0 ml of 6.00M HCl is added to 130 ml of $H_{2}$ O.