Answer:
The term Big Bang defines that the Universe has expanded from the ancient hot and thick primary situation at some fixed time in the past.
Big Bang theory refers to the origin of the Universe. In the beginning, universe is very heavy and small hot ball of matter. It was a point no bigger than the head of a pin when all the things squished with each other and universe is expanded with huge explosion of energy. Due to expansion, it is cooled and results in the formation of Stars and galaxies. After sometime, atoms formed like helium and hydrogen.
Thus, statement (1), (3) and (4) is correct whereas statement (2) and (5) is incorrect. the right answer is - (It expanded slowly), (Stars and galaxies formed,) (Atoms such as hydrogen and helium formed.)
Explanation:
The answer is A, a new chemical substance has to be formed for there to be a chemical change. This is because chemical change happens when a phase of matter changes due to chemicals.
Answer:
3.
Explanation:
- Al(OH)₃ reacts with HCl to produce AlCl₃ and water according to the balanced equation:
<em>Al(OH)₃ + 3 HCl → AlCl₃ + 3H₂O,</em>
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<em>It is clear that 1.0 mole of Al(OH)₃ reacts with 3.0 mole of HCl to produce 1.0 mole of AlCl₃ and 3.0 moles of H₂O,</em>
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<em>So, the coefficient of HCl is 3.</em>
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Answer:
Explanation:
We are given the specific heat and change in temperature, so we should use this heat formula:
where m is the mass, C is the specific heat capacity, and ΔT is the change in temperature.
We know the mass is 150 grams. The specific heat of water is 4.184 J/g °C.
Let's find the change in temperature.
Subtract the initial temperature from the final temperature.
- ΔT= final temp - initial temp
- final= 95.0 °C and initial= 10.0 °C
- ΔT= 95.0 °C - 10.0 °C= 85.0 °C
Now we know all the values:
Substitute them into the formula.
Multiply all three numbers together. Note that the grams (g) and degrees Celsius (°C) will cancel out. Joules (J) will be the only remaining unit.
<u>53,346 Joules</u> of heat are required.