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igor_vitrenko [27]
2 years ago
13

Which of there is an indication that a chemical reaction has occurred?

Chemistry
1 answer:
Komok [63]2 years ago
6 0
Answer is (b) , because a chemical change happened
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How much heat does a 100. g sample of copper absorb when its temperature increases by 30.0°C? The specific heat of copper is 0.3
erica [24]

Answer:

\boxed {\boxed {\sf B. \ 1170 \ Joules }}

Explanation:

We are asked to find how much heat a sample of copper absorbs when the temperature is increased.

Since we know the mass, temperature increase, and specific heat capacity, we can use the following formula to calculate heat.

q= mc \Delta T

The mass of the copper sample is 100 grams, the temperature is changed or increased by 30.0 degrees Celsius, and the specific heat of copper is 0.39 Joules per gram degrees Celsius.

  • m= 100 g
  • c= 0.39 J/g °C
  • ΔT= 30.0 °C

Substitute the values into the formula.

q= (100 \ g )(0.39 \ J/g \textdegree C ) (30.0 \textdegree C )

Multiply the first two values. Note that the units of grams cancel.

q= 39 \ J/ \textdegree C (30.0 \textdegree C )

Multiply again, this time the units of degrees Celsius cancel.

q= 1170 \ J

The copper sample absorbs <u>1170 Joules</u> of heat and <u>Choice B </u>is correct.

7 0
3 years ago
We can prove a theory to be correct by performing the right experiment. False or true
eimsori [14]

Answer:

true

Explanation:

because if you find the right answer that proves the theory to be correct.  

4 0
3 years ago
What is homologous series . Write it's characteristics
Anni [7]

Answer:

Homologous series is defined as a systematic order of structurally similar organic compound containing same functional group in their family and two adjacent members differ in their molecular formula by -CH2 unit.

Characteristics:

1.Various members of homologous series contain same functional group.

2.Various members of homologous series can be represented by common formula.

3. All members of a homologous series have almost similar chemical properties.

4. All members have common method of preparation.

5.Two successive members of homologous series have different chain length or difference in their molecular formula by -CH2 unit.

6.The members of homologous series show different physical properties.

4 0
2 years ago
How does the average velocity of molecules in a high-temperature gas compare to the average velocity of molecules of the same ga
IrinaK [193]

Answer:lower temp molecules act slower so they come closer together and heated molecules are more spaced out that is why when you put an ice cube in a hot pan the ice melts and turns into a liquid due to heat the molecules space out

Explanation:

8 0
2 years ago
How many moles of O2 are needed to react completely with 35.0 mol C2h2
Wittaler [7]

Hey There!:


2 C2H2 + 5 O2 = 4 CO2 + 2 H2O


2 moles C2H2 ----------- 5 moles O2

35.0 moles C2H2 ------- moles O2


moles O2 = 35.0 * 5 / 2


moles O2 = 87.5 moles


hope this helps!

6 0
2 years ago
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