The work needed to operate a machine is called work output O True O False

Water 2270g is heated until it just begins to boil. If the water absorbs 5.51 ×10^5 J of heat in the process, what was the initi

kolbaska11 [484]

Answer:

42.01 °C

Explanation:

Step 1: explain the problem

We have to find the initial temperature, when a certain amount of heat raises this sample of water to its boiling point ( 100 °C)

⇒this amount of heat = 5.51 x 10Δ^5 J

We will use the formule : Q = mcΔ T

with Q = heat transfer ( J)

with m = mass of the substance (g)

with c = specific heat ( J/g °C)

with Δ T = temperature change ( in °C or K)

Water has a specific heat of 4.186 J/g °C

Step 2 : Calculate the initial temperature

We have to rearrange the formule first:

Δ T = Q / mc

In this case we have :

Δ T = 5.51 * 10^5 J / 2270 g * 4.186 J/g °C = 57.99

⇒ The final temperature of the water is the boiling point (100 °C) and the change of temperature is 57.99. This means that the boiling point is 57.99 °C higher than the initial temperature.

This means : Δ T = Tboiling point - Tinitial

Δ T = 57.99 °C = 100 °C - Tinitial

Tinitial = 100 °C - 57.99 °C = 42.01 °C

The initial temperature of the water is 42.01 °C

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6 0

4 years ago

Calculate the number of sodium ions, perchlorate ions, Cl atoms and O atoms in 17.8 g of sodium perchlorate. Enter your answers

Degger [83]

17.8 g of sodium perchlorate contains 8.73 × 10²² Na⁺ ions, 8.73 × 10²² ClO₄⁻ ions, 8.73 × 10²² Cl atoms and 3.49 × 10²³ O atoms.

First, we will convert 17.8 g of NaClO₄ to moles using its molar mass (122.44 g/mol).

$17.8 g \times \frac{1mol}{122.44g} = 0.145 mol$

Next, we will convert 0.145 moles to molecules of NaClO₄ using Avogadro's number; there are 6.02 × 10²³ molecules in 1 mole of molecules.

$0.145 mol \times \frac{6.02 \times 10^{23}molecules }{mol} = 8.73 \times 10^{22}molecules$

NaClO₄ is a strong electrolyte that dissociates according to the following equation.

NaClO₄ ⇒ Na⁺ + ClO₄⁻

The molar ratio of NaClO₄ to Na⁺ is 1:1. The number of Na⁺ in 8.73 × 10²² molecules of NaClO₄ is:

$8.73 \times 10^{22}moleculeNaClO_4 \times \frac{1 ion Na^{+} }{1moleculeNaClO_4} = 8.73 \times 10^{22}ion Na^{+}$

The molar ratio of NaClO₄ to ClO₄⁻ is 1:1. The number of ClO₄⁻ in 8.73 × 10²² molecules of NaClO₄ is:

$8.73 \times 10^{22}moleculeNaClO_4 \times \frac{1 ion ClO_4^{-} }{1moleculeNaClO_4} = 8.73 \times 10^{22}ion ClO_4^{-}$

The molar ratio of ClO₄⁻ to Cl is 1:1. The number of Cl in 8.73 × 10²² ions of ClO₄⁻ is:

$8.73 \times 10^{22}ion ClO_4^{-} \times \frac{1 atomCl }{1ion ClO_4^{-}} = 8.73 \times 10^{22}atom Cl$

The molar ratio of ClO₄⁻ to O is 1:1. The number of O in 8.73 × 10²² ions of ClO₄⁻ is:

$8.73 \times 10^{22}ion ClO_4^{-} \times \frac{4 atomO }{1ion ClO_4^{-}} = 3.49 \times 10^{23}atom O$

17.8 g of sodium perchlorate contains 8.73 × 10²² Na⁺ ions, 8.73 × 10²² ClO₄⁻ ions, 8.73 × 10²² Cl atoms and 3.49 × 10²³ O atoms.

You can learn more Avogadro's number here: brainly.com/question/13302703

8 0

2 years ago

Can somebody help me

Anastaziya [24]

It would be:
2H2 + O2 -> 2H2O

5 0

3 years ago

A topaz crystal has an interplanar spacing (d) of 1.36 Å (1 Å =1×10^[−10] m). Calculate the wavelength of the X-ray that should

bija089 [108]

Answer:

7.0*10-11m or 70Å

Explanation:

From Bragg's equation, w=2dsinx/n

Since all the parameters are specified in the question, we can easily go ahead to obtain the wavelength but we must convert the spacing given in angstroms to meters using the conversion factor provided as shown in the solution below:

7 0

4 years ago

Examples of noble gases

LekaFEV [45]

Natural gas, desolate

4 0

3 years ago

The work needed to operate a machine is called work output O True O False​

The work needed to operate a machine is called work output O True O False