The question is listed in the image attached.

when you draw a bow across a violin string which kind of wave is created in the air surrounding the string

Lilit [14]

Answer:

When the string on a violin vibrates, waves move in both directions along the string, interfering with each other. These waves are standing waves.

Explanation:

What are Standing Waves?

The Standing Waves are waves generated due to the vibrational frequency that produces reflected waves capable of interfering with the incident waves.

8 0

1 year ago

Which substance can not be broken down by a chemical change?

frosja888 [35]

(4) Zirconium
This element is often used in the chemical production field, and as implants due to its high chemical resistance and stability.

8 0

2 years ago

The activation energy of a reaction is 56.9 kj/mol and the frequency factor is 1.5×1011/s. Part a calculate the rate constant of

Vanyuwa [196]

We will use Arrehenius equation

lnK = lnA -( Ea / RT)

R = gas constant = 8.314 J / mol K

T = temperature = 25 C = 298 K

A = frequency factor

ln A = ln (1.5×10 ^11) = 25.73

Ea = activation energy = 56.9 kj/mol = 56900 J / mol

lnK = 25.73 - (56900 / 8.314 X 298) = 2.76

Taking antilog

K = 15.8

5 0

3 years ago

8. What is the heat of reaction when hydrogen and oxygen combine to form water?

valina [46]

Answer:

The heat of reaction when hydrogen and oxygen combine to form water is :

Explanation:

Enthalpy Change = The enthalpy change for the formation of 1 mole of the substance from their standard state is called the enthalpy of formation.

This is intensive quantity as it is fixed for 1 mole .

Intensive properties = Those properties which are independent on the amount of the substance are intensive properties.

The value of these quantities does not get halve if you divide the substance into two equal parts. example , density, refractive index.

However , the enthalpy of reaction is extensive. Because on increasing the amount the value of the enthalpy also get doubles

Hence for this reaction :

$2H_{2}(g)+O_{2}\rightarrow 2H_{2}(l)$

Its value is -285.8 kJ for 1 mole

And here two moles are present . so the value of molar enthalpy is:

-285.8 x 2 = -571.6 kJ

8 0

3 years ago

The standard molar heat of fusion of ice is 6020 j/mol. calculate q, w, and ∆e for melting 1.00 mol of ice at 0◦c and 1.00 atm p

zysi [14]

Answer : q = 6020 J, w = -6020 J, Δe = 0

Solution : Given,

Molar heat of fusion of ice = 6020 J/mole

Number of moles = 1 mole

Pressure = 1 atm

Molar heat of fusion : It is defined as the amount of energy required to melt 1 mole of a substance at its melting point. There is no temperature change.

The relation between heat and molar heat of fusion is,

$q=\Delta H_{fusion}(\frac{Mass}{\text{ Molar mass}})$ (in terms of mass)

or, $q=\Delta H_{fusion}\times Moles$ (in terms of moles)

Now we have to calculate the value of q.

$q=6020J/mole\times 1Mole=6020J$

When temperature is constant then the system behaves isothermally and Δe is a temperature dependent variable.

So, the value of $\Delta e=0$

Now we have to calculate the value of w.

Formula used : $\Delta e=q+w$

where, q is heat required, w is work done and $\Delta e$ is internal energy.

Now put all the given values in above formula, we get

$0=6020J+w$

w = -6020 J

Therefore, q = 6020 J, w = -6020 J, Δe = 0

3 0

3 years ago