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2 years ago

Which does heat represent ?

1 answer:

7 0

it represents a physical change. it is not a chemical change because its chemical formula does not change unless combustion is involved.

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What is extrapolation?

bixtya [17]

Answer:

A. Predicting data that fall beyond a known data point

Explanation:

Extrapolating is unreliable because you are predicting data outside of the data range - anything could happen for the data to stop following the trend or pattern

8 0

2 years ago

A 3.31-g sample of lead nitrate, Pb(NO3)2, molar mass = 331 g/mol, is heated in an evacuated cylinder with a volume of 2.53 L. T

Dahasolnce [82]

Answer:

0.486atm is the pressure of the cylinder

Explanation:

1 mole of Pb(NO₃)₂ descomposes in 4 moles of NO2 and 1 mole of O2. That is 1 mole descomposes in 5 moles of gas.

To find the pressure of the cylinder, we need to find moles of gas produced, and using general gas law we can determine the pressure of the gas:

Moles Pb(NO₃)₂ and moles of gas:

3.31g * (1mol / 331g) = 0.01 moles of Pb(NO₃)₂.

That means moles of gas produced is 0.05 moles.

Pressure of the gas:

Using PV = nRT

P = nRT/V

Where P is pressure (Incognite)

V is volume (2.53L)

R is gas constant (0.082atmL/molK)

T is absolute temperature (300K)

And n are moles of gas (0.05 moles)

P = 0.05mol*0.082atmL/molK*300K / 2.53L

P = 0.486atm is the pressure of the cylinder

3 0

2 years ago

Which of the following pairs of elements is most likely to share one or more pairs of electrons between their nuclei?

Nana76 [90]

Sulfur and chlorine. Explanation: A covalent bond is formed by two non-metals with similar electronegativities. As a consequence, they share one or more pairs of electrons between their nuclei

3 0

2 years ago

How do you find the molar mass of a hydrate

Darya [45]

If you mean hydrate as in MgSO4 · 7H2O, then simply find the molar mass of each element you see.

For the example above, that means you would add the molar mass (found on the periodic table) of Mg, then S, then 4(O), 14(H), and 7(O).

The results would be your molar mass for the hydrate.

I hope this is what you meant by your question!

6 0

2 years ago

Suppose a solution was too concentrated for an accurate reading with the spectrophotometer. The concentrated solution was dilute

yan [13]

Using the law of dilution:

initial Molarity = 3.5x10⁻⁶ M

Initial volume = 4.00 mL

final Molarity = ??

final volume = 1.00 mL

Therefore:

Mi x Vi = Mf x Vf

(3.5x10⁻⁶) x 4.00 = Mf x 1.00

1.4x10⁻⁵ = Mf x 1.00

Mf = 1.4x10⁻⁵ / 1.00 =

1.4x10⁻⁵ M

5 0

2 years ago