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Alexxandr [17]
2 years ago
8

1. Name three obstacles that Mendeleev faced in his life? ​

Chemistry
1 answer:
Fittoniya [83]2 years ago
3 0

Answer:

was difficult to place isotopes of elements as they have the same chemical properties but different atomic masses. It was not possible to predict how many elements could be discovered between two heavy elements as the rise in atomic mass is not uniform.

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a 4.50 g coin of copper absorbed 54 calories of heat. what was the final temperature of the copper if the initial temperature wa
vlada-n [284]

Answer:

Final temperature =  T₂ = 155.43 °C

Explanation:

Specific heat capacity:

It is the amount of heat required to raise the temperature of one gram of substance by one degree.

Formula:

Q = m.c. ΔT

Q = amount of heat absorbed or released

m = mass of given substance

c = specific heat capacity of substance

ΔT = change in temperature

Given data:

Mass of coin = 4.50 g

Heat absorbed = 54 cal

Initial temperature = 25 °C

Specific heat of copper = 0.092 cal/g °C

Final temperature = ?

Solution:

Q = m.c. ΔT

ΔT = T₂ -T₁

Q = m.c. T₂ -T₁

54 cal = 4.50 g × 0.092 cal/g °C ×  T₂ -25  °C

54 cal = 0.414 cal/ °C ×  T₂ -25  °C

54 cal /0.414 cal/ °C =  T₂ -25  °C

130.43 °C  =  T₂ -25 °C

130.43 °C + 25 °C = T₂

155.43 °C = T₂

4 0
2 years ago
Need help ASAP with this question
Karo-lina-s [1.5K]

Answer: noble gasses

Explanation: zoom on on the red section and look at the key for what red means.

8 0
2 years ago
What is the molarity of a sodium hydroxide solution containing 2 moles of NaOH with a volume of .5L?
Maksim231197 [3]

Answer:

0.4M NaOH

Explanation:

Molarity, M, is an unit of concentration widely used defined as the ratio between moles of solute (In this case, NaOH) and volume of solution in liters.

As the solution contains 2 moles of NaOH-Moles of solute- in 5L of solution, the molarity is:

2 moles NaOH /  5L =

<h3>0.4M NaOH</h3>
5 0
2 years ago
A car starts from rest. It takes 6.0 seconds for the car to accelerate to 5 m/s2 W. What is the final velocity?
Artyom0805 [142]

Answer: 30 m/s

Explanation:

Use the first kinematic equation for linear motion

V=V_i+at\\V=0+(5)(6)\\v=30m/s

5 0
3 years ago
CaC2 + 2H2O → C2H2 + Ca(OH)2 If 2.8 moles of CaC2 are consumed in this reaction, how many grams of H2O are needed?
Strike441 [17]

Answer:

Cac2 is a answer please mark me brainliest

8 0
2 years ago
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