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3 years ago

Imagine a pulley system with four fixed and four moveable pulleys.

Chemistry

2 answers:

Paul [167]3 years ago

8 0

Answer:

Explanation:

aleksklad [387]3 years ago

4 0

a fixed pulley is a load multiplier and a movable multiplier is a speed multiplier

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The value of ΔG° at 181.0 °C for the formation of calcium chloride from calcium metal and chlorine gas is ________ kJ/mol. At 25

aleksandr82 [10.1K]

Answer:

$\Delta G^{0}$ at 181.0 $^{0}\textrm{C}$ is -723.3 kJ/mol.

Explanation:

We know, $\Delta G^{0}=\Delta H^{0}-T\Delta S^{0}$

where, T is temperature in kelvin.

Let's assume $\Delta H^{0}$ and $\Delta S^{0}$ does not change in the temperature range 25.0 $^{0}\textrm{C}$ - 181.0 $^{0}\textrm{C}$ .

$181.0^{0}\textrm{C}$ = (273+181.0) K = 454.0 K

Hence, at 181.0 $^{0}\textrm{C}$ , $\Delta G^{0}=(-795.8kJ/mol)-[(454.0 K)\times (-159.8\times 10^{-3}kJ/K.mol)]$

= -723.3 kJ/mol

5 0

3 years ago

Calculate the heat (in J) required to raise the temperature of 3.02 g of solid silver from 22.3 degrees Celsius so solid silver

Furkat [3]

Answer: 17.9 joules

Explanation:

The quantity of Heat Energy (Q) required to heat solid silver depends on its Mass (M), specific heat capacity (C) and change in temperature (Φ)

Thus, Q = MCΦ

Given that,

Q = ?

Mass= 3.02g

C = 0.24J/g°C

Φ = (Final temperature - Initial temperature)

= 47°C - 22.3°C = 24.7°C

Then, Q = MCΦ

Q = 3.02g x 0.240J/g°C x 24.7°C

Q = 17.9 Joules

Thus, 17.9 joules of heat isrequired.

7 0

3 years ago

A sound wave from a jackhammer travels through a section of concrete with a fixed frequency. At the concrete's boundary is mud.

Ira Lisetskai [31]

Answer:

It might be too late now, but the correct answer for the question is B.

Explanation:

According to the graph you can see when it hit the boundary of the mud it curved downward making the direction change; which then the mud probably had a hollow shell, where the speed was moving much faster.

6 0

3 years ago

Read 2 more answers

Match the sentences with the steps of the scientific method.

Harrizon [31]

Answer: use your brain

Explanation:

I have one

6 0

3 years ago

Gold is alloyed (mixed) with other metals to increase its hardness in making jewelry.

KiRa [710]

Answer:

A) 54.04%

B) 13-karat

Explanation:

A) From the problem we have

1) Mg + Ms = 9.40 g

2) Vg + Vs = 0.675 cm³

Where M stands for mass, V stands for volume, and g and s stand for gold and silver respectively.

We can rewrite the first equation using the density values:

3) Vg * 19.3 g/cm³ + Vs * 10.5 g/cm³ = 9.40

So now we have a system of two equations (2 and 3) with two unknowns:

We express Vg in terms of Vs:

Vg + Vs = 0.675 cm³

Vg = 0.675 - Vs

We replace the value of Vg in equation 3:

Vg * 19.3 + Vs * 10.5 = 9.40

(0.675-Vs) * 19.3 + Vs * 10.5 = 9.40

13.0275 - 19.3Vs + 10.5Vs = 9.40

-8.8 Vs + 13.0275 = 9.40

Vs = 0.412 cm³

Now we calculate Vg:

Vg + Vs = 0.675 cm³

Vg + 0.412 cm³ = 0.675 cm³

Vg = 0.263 cm³

We calculate Mg from Vg:

0.263 cm³ * 19.3 g/cm³ = 5.08 g

We calculate the mass percentage of gold:

5.08 / 9.40 * 100% = 54.04%

We multiply 24 by the percentage fraction:

24 * 54.04/100 = 12.97-karat ≅ 13-karat

4 0

3 years ago