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2 years ago

Please help!

Chemistry

2 answers:

ANEK [815]2 years ago

8 0

Answer:

A- Physical, B- Chemical, C- chemical, D- Physical

Explanation:

A is physical because you can see it changing its form is changing.

B is Chemical because a new substance is formed creating the orange color of rust.

C is a Chemical reaction because it is being broken down so the banana itself is changing not just how we see it.

D is physical because we are just changing the shape/ size of the item, not anything to do with its substances.

motikmotik2 years ago

8 0

Answer:

a. physical change, it is reverse reversible since no new substance is created.

b.chemical change, The iron reacts with water and oxygen to form hydrated iron(III) oxide, which we see as rust.

c. chemical change, Bananas contain compounds known as polyphenol oxidases and iron-containing chemicals. These chemicals react with oxygen to turn the fruit brown.

d. physical change, there is no new substance created, and there is no change in the original composition of wood.

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From the stoichiometry of the combustion reaction, we can see that 7.4 L of oxygen is consumed.

<h3>What is combustion?</h3>

Combustion is a reaction in which a substance is burnt in oxygen. The equation of the reaction is; C4H10O(l) + 6O2 (g) → 4CO2 (g) + 5H2O(l)

We can obtain the number of moles of CO2 from;

PV = nRT

n = 1.02 atm * 7.15 L/0.082 atm LK-1mol-1 * (125 + 273) K

n = 7.29 /32.6

n = 0.22 moles

If 6 moles of oxygen produces 4 moles of CO2

x moles of oxygen produces 0.22 moles of CO2

x = 0.33 moles

1 mole of oxygen occupies 22.4 L

0.33 moles of oxygen occupies 0.33 moles * 22.4 L/ 1 mole

= 7.4 L of oxygen

Learn more about stoichiometry: brainly.com/question/13110055

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2 years ago

1. Marisa determined the melting point of a substance to be 24.5C. Find the percent error of her measurement if the actual melti

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Answer:

$\%\ Error = 21.5\%$

Explanation:

Given

$Measured = 24.5$

$Actual = 31.2$

Required

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First, we need to determine the difference in the measurement

$Difference = |Actual - Measured|$

$Difference = |31.2 - 24.5|$

$Difference = |6.7|$

$Difference = 6.7$

The percentage error is calculated as thus:

$\%\ Error = \frac{Difference * 100\%}{Actual}$

$\%\ Error = \frac{6.7 * 100\%}{31.2}$

$\%\ Error = \frac{670\%}{31.2}$

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$\%\ Error = 21.5\%$ <em>approximated</em>

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3 years ago

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Answer and Explanation:

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Answer:

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3 years ago

Qué tipo de reacción es el siguiente? CH4 + 02<br><br> CO2 + H2O

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Answer:

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2 years ago

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