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UNO [17]
3 years ago
13

Which observation is the best indication that a chemical reaction has occurred?

Chemistry
2 answers:
saul85 [17]3 years ago
4 0

Answer:B

Explanation:

Vitek1552 [10]3 years ago
3 0

Answer:

B: Presence of ashes

Explanation:

Burning molecules turns them into other molecules

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A student performs an experiment to find the percentage of water in a hydrate. He determines that the hydrate contains 22% water
Stels [109]

Answer:

A feasible error could have been the removal of the sample before all water evaporated.

Explanation:

In order to determine the percentage of water in an hydrate, an experiment that could be performed is the heating of the sample until the mass does not change. If the student heated the sample an insufficient amount of time, water will be present in the sample, thus reducing the percentage reported.

4 0
3 years ago
What is the conjugate acid in the following equation:
yanalaym [24]

Answer:

HNO₂

Explanation:

An acid is a proton donor; a base is a proton acceptor.

Thus, NO₂⁻ is the base, because it accepts a proton from the water.

H₂O is the acid, because it donates a proton to the nitrite ion.

The conjugate base is what's left after the acid has given up its proton.

The conjugate acid is what's formed when the base has accepted a proton.

NO₂⁻/HNO₂ make one conjugate acid/base pair, and H₂O/OH⁻ are the other conjugate acid/base pair.

NO₂⁻ + H₂O ⇌ HNO₂ + OH⁻

base     acid     conj.      conj.

                        acid       base

5 0
3 years ago
There is a gas pressure in a container that is 123kPa what is the pressure in atmospheres ?
Vera_Pavlovna [14]

Answer:

In strict SI units (highly recommended), express n in moles, R is the universal gas constant R=8.314Jmol−K , T is the temperature in Kelvins, and the volume V is in m3 . The resulting pressure P will be in Pa. R=0.082054L−atmmol−K , in which case the pressure is calculated in atm.

8 0
3 years ago
What does a useful scientific explanation include ??
ArbitrLikvidat [17]

Answer: scientific explanation

Explanation:

A really good scientific explanation should do two main things: It should explain all the observations and data we have. It should allow us to make testable predictions that we can check using future experiments.

7 0
3 years ago
Pls that is the picture ​
Fiesta28 [93]
Do what it says easy
3 0
3 years ago
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