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3 years ago

In which situation is maximum work considered to be done by a force?

Chemistry

1 answer:

Lelu [443]3 years ago

6 0

Answer:

Option E

Explanation:

As work is dot product of force and displacement

W=FdCos0

As Cos 0=1 so W=F.d(1)

W=F.d

as Cos 90=0 so no work will be done when angle between force and displacement is 90 degree. At angle between force and displacement is 180 degree then negative value com as Cos 180= -1

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Which chemical is least likely to undergo a chemical reaction

Anestetic [448]

The answer is A, neon.
The reason for this is because neon is a noble gas, which means that it doesn't react with other elements as well.
Hope this helps!

8 0

4 years ago

riddle time We are two separate things but very much alike. We can be life long or the lesson of your life. We grant you happine

Eva8 [605]

Choices/ Decisions. Hope this helps.

8 0

3 years ago

Photons of infrared radiation are responsible for much of the warmth we feel when holding our hands before a fire. These photons

KIM [24]

Answer:

$8.3\cdot 10^{22}$ photons

Explanation:

The energy of a photon is given by

$E_1 = \frac{hc}{\lambda}$

where

$h=6.63\cdot 10^{-34} Js$ is the Planck constant

$c=3.0\cdot 10^8 m/s$ is the speed of light

$\lambda$ is the photon wavelength

Here we have

$\lambda=1.5\cdot 10^{-6} m$

So, the energy of 1 of these infrared photons is

$E_1=\frac{(6.63\cdot 10^{-34})(3\cdot 10^8)}{1.5\cdot 10^{-6}}=1.32\cdot 10^{-19} J$

The amount of energy needed to increase the temperature of the cup of water is:

$E=mC\Delta T$

where

m = 175 g is the mass

$C=4.186 J/gC$ is the specific heat capacity

$\Delta T=40-25=15^{\circ}C$ is the increase in temperature

So,

$E=(175)(4.186)(15)=10,988 J$

Therefore, the number of photons needed is:

$n=\frac{E}{E_1}=\frac{10,988}{1.32\cdot 10^{-19}}=8.3\cdot 10^{22}$

5 0

3 years ago

Which action would shift this reaction away from solid calcium fluoride and toward the dissolved ions?a) adding calcium ionsb) a

Mila [183]

Answer:

c) removing fluoride ions.

Explanation:

Hello!

In this case, for this solubility product problem, it is very convenient to write the undergoing ionization reaction:

$CaF_2(s)\rightleftharpoons Ca^{2+}(aq)+2F^-(aq)$

In such a way, via the Le Chatelier's principle, we remember that the addition of reactants shifts the reaction towards products, adding products shifts the reaction towards reactants, removing reactants shifts the reaction towards reactants and removing products shifts the reaction towards products. In means, that the best way to shift this reaction away from solid calcium fluoride and toward the dissolved ions is c) removing fluoride ions, because it is a product and its removal favors the formation of more products.

Best regards!

8 0

3 years ago

How many nitrogen atoms are present in 0.150 mol of zn(no3)2?

gregori [183]

First calculate number of Nitrogen atoms contained by 1 mole of Zn(NO₃)₂,

As one formula unit of Zn(NO₃)₂ contains 2 Nitrogen atoms, then one mole of Zn(NO₃)₂ will contain,

= 2 × 6.022 × 10²³

= 1.20 × 10²⁴ Atoms of Nitrogen / mole

Now, calculate number of Nitrogen Atoms in 0.150 moles of  Zn(NO₃)₂.
As,
1 mole of  Zn(NO₃)₂ contained = 1.20 × 10²⁴ atoms of N
Then,
0.15 mole of  Zn(NO₃)₂ will contain = X atoms of N
Solving for X,

X = (0.15 mol × 1.20 × 10²⁴ atom) ÷ 1 mol

X = 1.80 × 10²⁴ Atoms of Nitrogen
Result:
So, 0.15 mole of  Zn(NO₃)₂ contains 1.80 × 10²⁴ atoms of Nitrogen.

8 0

3 years ago