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3 years ago

Explain how the system of the flask and the balloon illustrates the conservation of mass.

1 answer:

4 0

Both containers prevent the escape of matter of the reaction into an uncontrolled space, therefore it is a closed system (not isolated, since energy can still go in and out).

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If you add heat to a solid, the particles will... (choose all that apply) *

elena55 [62]

Answer: Expand and speeds up

Explanation:

5 0

3 years ago

Convert 15.2 moles of K to atoms of K.

choli [55]

Answer:

$\boxed {\boxed {\sf 9.15*10^{24} \ atoms \ K}}$

Explanation:

To convert atoms to moles, Avogadro's Number must be used: 6.022*10²³.

This tells us the amount of particles (atoms, molecules, etc.) in 1 mole of a substance. In this case it is the atoms of potassium. We can create a ratio.

$\frac {6.022*10^{23} \ atoms \ K }{ 1 \ mol \ K }$

Multiply by the given number of moles: 15.2

$15.2 \ mol \ K *\frac {6.022*10^{23} \ atoms \ K }{ 1 \ mol \ K }$

The moles of potassium cancel.

$15.2 *\frac {6.022*10^{23} \ atoms \ K }{ 1 }$

The denominator of 1 can be ignored.

$15.2 * {6.022*10^{23} \ atoms \ K }{$

Multiply.

$9.15344*10^{24} \ atoms \ K$

The original measurement of moles has 3 significant figures, so our answer must have the same. For the number we calculated that is the hundredth place. The 3 in the thousandth place tells us to leave 5.

$9.15*10^{24} \ atoms \ K$

In 15.2 moles of potassium, there are <u>9.15*10²⁴ atoms of potassium.</u>

3 0

3 years ago

Thomas had a volume of 8.5 g of sodium chloride. What is the molar mass.?

alina1380 [7]

Answer:

58.44 g/mol

Explanation:

In this problem, make sure to remember that volume is measured in mL, L or any other units of volume. Remember that g represents grams, and grams is a measure of mass.

However, independent of what mass or what volume we take, molar mass is known to be an intensive property. That is, molar mass doesn't depend on any external conditions or any measurements.

Molar mass solely depends on the chemical structure of a compound and is a constant number at any given conditions.

In this problem, we are given sodium chloride, NaCl. In order to find its molar mass, we need to refer to the periodic table, find the atomic masses of Na and Cl and then add them up to have the molar mass of NaCl:

$M_{NaCl} = M_{Na} + M_{Cl} = 22.99 g/mol + 35.453 g/mol = 58.44 g/mol$

5 0

3 years ago

An iron bar at 200c is placed in thermal contact with an identical iron bar at 120c in an isolated system

Step2247 [10]

Conduction: In the conduction, the heat is transferred from the hotter body to the colder body until the temperature on both bodies are equal.

In thermal equilibrium, there is no heat transfer as the heat is transferred till the temperature on the bodies are not same.

In the given problem, an iron bar at 200°C is placed in thermal contact with an identical iron bar at 120°C in an isolated system. After 30 minutes, the thermal equilibrium is attained. Then, the temperature on both iron bars are equal.Both iron bars are at 160°C in an isolated system.

But in an open system, the temperatures of the iron bars after 30 minutes would be less than 160°C. There will be heat lost to the surrounding. The room temperature is 25°C. There will be exchange of the heat occur between the iron bars and the surrounding. But It would take more than 30 minutes for both iron bars to reach 160°C because heat would be transferred less efficiently.

7 0

3 years ago

Read 2 more answers

Do all forms of radioactive decay change the identity of the original element?

hoa [83]

Explanation:

<h3>yes, Radioactive decay involves the emission of a particle and/or energy as one atom changes into another. In most instances, the atom changes its identity to become a new element.</h3>

5 0

2 years ago