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Alexxx [7]
3 years ago
11

During science lab, some students added small pieces of magnesium ribbon to 10 mL of hydrochloric acid. They noticed that bubble

s formed, the test tube got hot, and the magnesium disappeared.
Which is a sign that a chemical reaction has taken place in this experiment?
Chemistry
2 answers:
stiv31 [10]3 years ago
4 0
Your answer would be a change in odor! Hope this helps! ;D
Stels [109]3 years ago
4 0

Answer:

C

Explanation:

Release of heat energy

The test tube got hot; that's a sign that heat energy is being released. This is an exothermic chemical reaction. Change in odor and color are signs of a chemical change but do not occur in this case.

(Correct in USA Test Prep too!)

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a. For the reaction 2H2 + 02→ 2H20, how many moles of water can be produced from 6.0 mol of oxygen? 2.0 mol b. 6.0 mol 12 mol d.
pickupchik [31]

Explanation:

from the equation 1 mole of O2 will give 2 moles of H2O then 6.0 moles of O2 will give x

6.0*2 moles/ 1 mole

= 12 moles

this implies that, 6.0 moles of O2 will give = 12 moles of water

3 0
3 years ago
How do the particles that are dispersed in a colloid differ from the particles suspended in a suspension?
Fed [463]

Answer:B, the colloid particles are larger.

PLEASE GIVE BRAINLIEST AND WATCH OUT BEHIND YOU

5 0
3 years ago
What is the mass of oxygen in 3.34 g of potassium permanganate?
3241004551 [841]

Answer:

1.35 g

Explanation:

Data Given:

mass of Potassium Permagnate (KMnO₄) = 3.34 g

Mass of Oxygen: ?

Solution:

First find the percentage composition of Oxygen in Potassium Permagnate (KMnO₄)

So,

Molar Mass of KMnO₄ = 39 + 55 + 4(16)

Molar Mass of KMnO₄ = 158 g/mol

Calculate the mole percent composition of  Oxygen in Potassium Permagnate (KMnO₄).

Mass contributed by Oxygen (O) = 4 (16) = 64 g

Since the percentage of compound is 100

So,

                        Percent of Oxygen (O) = 64 / 158 x 100

                        Percent of Oxygen (O) = 40.5 %

It means that for ever gram of Potassium Permagnate (KMnO₄) there is 0.405 g of Oxygen (O) is present.

So,

for the 3.34 grams of Potassium Permagnate (KMnO₄) the mass of Oxygen will be

                  mass of Oxygen (O) = 0.405 x 3.34 g

                  mass of Oxygen (O) = 1.35 g

5 0
3 years ago
mr. Rose asked his student to draw a quadrilateral with four unequal sides. An example of this kind of quadrilateral
777dan777 [17]
Think of w shape with 4 sides the shape I know tat is Quadrilateral is a square
8 0
3 years ago
If the pressure on a gas at -73°C is doubled but its volume is held constant, what will its final temperature be in degrees Cels
Gre4nikov [31]

Answer:

127°C

Explanation:

This excersise can be solved, with the Charles Gay Lussac law, where the pressure of the gas is modified according to absolute T°.

We convert our value to K → -73°C + 273 = 200 K

The moles are the same, and the volume is also the same:

P₁ / T₁ = P₂ / T₂

But the pressure is doubled so: P₁ / T₁ = 2P₁ / T₂

P₁ / 200K = 2P₁ / T₂

1 /2OOK = (2P₁ / T₂) / P₁

See how's P₁ term is cancelled.

200K⁻¹ = 2/ T₂

T₂ = 2 / 200K⁻¹  → 400K

We convert the T° to C → 400 K - 273 = 127°C

4 0
3 years ago
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