What is the sum of the coefficients for the following unbalanced equation?

A common radio wavelength observed coming from astronomical objects is 21 cm. What temperature is associated with this radiation

qaws [65]

Answer:

The temperature associated with this radiation is 0.014K.

Explanation:

If we assume that the astronomical object behaves as a black body, the relation between its <em>wavelength</em> and <em>temperature</em> is given by Wien's displacement law.

$\lambda_{max}=\frac{b}{T}$

where,

λmax is the wavelength at the peak of emission

b is Wien's displacement constant (2.89×10⁻³ m⋅K)

T is the absolute temperature

For a wavelength of 21 cm,

$T=\frac{b}{\lambda _{max} } = \frac{2.89 \times 10^{-3} m.K }{0.21m} =0.014K$

8 0

3 years ago

Ensure you write the states of the reactants and products.

slamgirl [31]

<h3>Answer:</h3>

Phosphoric acid reacts with magnesium hydroxide to produce magnesium phosphate and water via the following reaction:

2H3PO4 + 3Mg(OH)2 → Mg3(PO4)2 + 6H2O

(solid) (solid) (solid) (liquid)

<h3>Explaination:</h3>

This is a typical neutralization reaction of an acid with a base to form a salt and water. The reaction is exothermic, gives off heat,

ΔH < 0 , and may be balanced by adding balancing numbers in front, ie adding molecules, in order to ensure that the total number of atoms of each element is the same on the left and right hand sides of the equation.

Doing so we obtain :

2H3PO4 + 3Mg(OH)2 → Mg3(PO4)2 + 6H2O

(solid) (solid) (solid) (liquid)

<h3>hope it helps :)</h3>

6 0

3 years ago

Read 2 more answers

A velocity vs time graph is a graph that shows the relationship between the velocity of an object over time. is plotted on the x

S_A_V [24]

A graph shows a relationship between two variables: independent and dependent. The dependent variable is in the y-axis, while the independent variable is in the x-axis. When it says, plot velocity against time, that means that velocity is in the y-axis in meters per second, and time is in the x-axis in seconds.

An example of a velocity vs time graph is shown in the attached picture. In this example, the motion is in constant acceleration. This is because it is linear, thereby, the slope is constant. If you want to find the instantaneous velocity at a certain time, create a vertical line from the x-axis until it reaches the diagonal line. Then, draw a horizontal line towards the y-axis to know the value of the velocity.

8 0

3 years ago

Read 2 more answers

Why is the transition state of the reaction always so high in energy? A. Breaking bonds always requires energy, and getting to t

lbvjy [14]

The answer is B. Forming bonds requires energy and breaking bonds releases energy. The transition state is the highest point in one reaction energy profile. Before the transition state, the energy increases which means transition state absorbs energy.

4 0

3 years ago

Read 2 more answers

Please help me, act fast

monitta

Answer:

10g of Pb.

Explanation:

To know which answer is correct, let us calculate the change in the temperature of each substance. This is illustrated below:

For water:

Mass (M) = 10g

Specific heat capacity (C) = 4.18J/g°C

Change in temperature (ΔT) = ..?

Heat (Q) = 100J

Q = MCΔT

Divide both side by MC

ΔT = Q/MC

ΔT = 100 / (10 x 4.18)

ΔT = 2.4°C

Therefore, the change in the temperature of water is 2.4°C

For Ag:

Mass (M) = 10g

Specific heat capacity (C) = 0.235J/g°C

Change in temperature (ΔT) = ..?

Heat (Q) = 100J

Q = MCΔT

Divide both side by MC

ΔT = Q/MC

ΔT = 100 / (10 x 0.235)

ΔT = 42.6°C

Therefore, the change in the temperature of Ag is 42.6°C

For Ca:

Mass (M) = 10g

Specific heat capacity (C) = 0.650J/g°C

Change in temperature (ΔT) = ..?

Heat (Q) = 100J

Q = MCΔT

Divide both side by MC

ΔT = Q/MC

ΔT = 100 / (10 x 0.650)

ΔT = 15.4°C

Therefore, the change in the temperature of Ca is 15.4°C

For Fe:

Mass (M) = 10g

Specific heat capacity (C) = 0.449J/g°C

Change in temperature (ΔT) = ..?

Heat (Q) = 100J

Q = MCΔT

Divide both side by MC

ΔT = Q/MC

ΔT = 100 / (10 x 0.449)

ΔT = 22.3°C

Therefore, the change in the temperature of Fe is 22.3°C

For Pb:

Mass (M) = 10g

Specific heat capacity (C) = 0.160J/g°C

Change in temperature (ΔT) = ..?

Heat (Q) = 100J

Q = MCΔT

Divide both side by MC

ΔT = Q/MC

ΔT = 100 / (10 x 0.160)

ΔT = 62.5°C

Therefore, the change in the temperature of Pb is 62.5°C

Summary:

Substance >> Change in temperature

Water >>>>>> 2.4°C

Ag >>>>>>>>> 42.6°C

Ca >>>>>>>>> 15.4°C

Fe >>>>>>>>> 22.3°C

Pb >>>>>>>>> 62.5°C

From the calculations made above, Pb has the greatest change in temperature

7 0

3 years ago