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yKpoI14uk [10]
2 years ago
13

How many moles of MgCl2 are there in 305 g of the compound? Answer and units

Physics
1 answer:
Alona [7]2 years ago
8 0
Wrong subject.  Expect that to be in chemistry.

Here it is:

One mole of a compound/element contains the weight in grams equal to the sum of the molecular mass.
For MgCL2,
Mg=24.30
Cl=35.45
so the molecular mass = 24.30+2*35.45=24.30+70.9=95.20 (approximately).
=>
One mole of MgCl2 weighs 95.20 g.

305 g of MgCl2 = 305/95.20 = 3.20 moles, to 3 significant figures

Edit: improved accuracy of atomic masses.
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Find the current passing through each of the 3 resistors connected parallel to each other as shown in the figure (i1, i2, I3). S
Thepotemich [5.8K]

Answer:

I1 = ε/R1

I2 = ε/R2

I3 = ε/R3

Explanation:

From the image, we see that the resistors are connected in parallel. This means that the voltage passing through them is the same.

Now, formula for current is; I = V/R

In this case, V which is voltage is denoted by ε.

Thus;

I1 = ε/R1

I2 = ε/R2

I3 = ε/R3

3 0
2 years ago
If my weight on Earth is 140lbs, what is my mass?
SashulF [63]

Answer:

63.57 kg

Explanation:

weight = 140 lbs

Let the mass  is m.

1 lbs = 4.45 N

The weight of an object is defined as the force with which our earth attracts the body towards its centre.

Weight is the product of mass of the body and the acceleration due to gravity of that planet.

W = m x g

On earth surface g = 9.8 m/s^2

Now convert lbs in newton

So, 140 lbs = 140 x 4.45 = 623 N

So, m x 9.8 = 623

m = 63.57 kg

Thus, the mass is 63.57 kg.

5 0
3 years ago
2. (1) A piece of rubber is 50 cm long when a weight of
Harrizon [31]

Answer

By F = -kx {-ve just indicating the sign of the force}

=>35 = k x (85-50) x 10^-2

=>k = 100 N/m

Again by F = -kx

8 0
3 years ago
6. The momentum of a 30.0 g bird with a speed of 12 m.s-1 is 0.36 kg.m.s-1. What will be its momentum 12s later if a constant .0
Keith_Richards [23]

Answer:

Explanation:

initial momentum = .36 kg.m.s⁻¹

negative impulse = force x time = .02 x 12 = .24 kg.m.s⁻¹

final momentum - initial momentum = impulse

final momentum = initial momentum + impulse

= .36 - .24

= .12 kg.m.s⁻¹

7 0
2 years ago
Silver has a work function of 4.5 eV . Part A What is the longest wavelength of light that will release an electron from a silve
uranmaximum [27]

Answer:

λ = 2.7608 x 10⁻⁷ m = 276.08 nm

Explanation:

The work function of a metallic surface is the minimum amount of photon energy required to release the photo-electrons from the surface of metal. The work function is given by the following formula:

Work Function = hc/λ

where,

Work Function = (4.5 eV)(1.6 x 10⁻¹⁹ J/1 eV) = 7.2 x 10⁻¹⁹ J

h = Plank's Constant = 6.626 x 10⁻³⁴ J.s

c = speed of light = 3 x 10⁸ m/s

λ = longest wavelength capable of releasing electron.

Therefore,

7.2 x 10⁻¹⁹ J = (6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/λ

λ = (6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(7.2 x 10⁻¹⁹ J)

<u>λ = 2.7608 x 10⁻⁷ m = 276.08 nm</u>

7 0
3 years ago
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