Answer:
This is because of the release of hydrogen gas in the reaction.
Explanation:
Metals react with water and produce a metal oxide and hydrogen gas. It also starts floating due to the bubbles of hydrogen gas sticking to its surface.
For eg:
<u>2Mg. + 2H2O --------> 2MgOH + H2</u>
Here,
Metal taken is <u>magnesium(2Mg)</u> which when reacts with <u>water(2H2O)</u> to form its <u>oxide form (2MgOH)</u> and <u>hydrogen gas(H2)</u> is released which comes outside water as bubbles.
Answer:
C. H₂SO₄
Explanation:
Given expression:
H₂O + SO₃ → H₂SO₄
In the chemical reaction, the product and the reactant have the same species.
Chemical reactions obeys the law of conservation of matter.
This way, atoms combine with one another to give a desired product. The products will contain a mix of the reactants.
- Fluorine is not part of the reactants
- Carbon is not part of the reactants
- Carbon is not part of the reactants.
For a first order reaction, the half life is inversely proportional to the rate constant.
The formula is
half life = ln(2)/k = 0.693/k
where k is the rate constant
t = 5.50 minutes
k = ln(2)/5.50 = 0.126 min^-1
Your rate constant is 0.126 min^-1.
The final temperature is -138 °C.
Explanation:
Using the equation of specific heat
We can easily find the final temperature of a 73.174 g of copper sample. As we know that specific heat is the amount of energy required to raise the temperature of the object to 1°C.
The specific heat of copper is known as 0.387 J/g°C and the initial temperature is said as 102 °C . The mass is given as 73.174 g. The heat released is 6800 J.
Since the heat is released the Q value will be negative.
Thus, the final temperature is -138 °C.
