Answer : The correct answer is 109.
Explanation :
Significant figure : It is defined as the each digits of a number have meaning or contribute to the value of the number.
The addition of given digits is,
43.2 + 50.0 + 16.0 = 109.2
As per the question, the given digits has 3 significant figures. But the answer after addition is 109.2 has 4 significant figures.
The addition rule of significant rule is the least precise number of significant figure in any number of the problem determines the number of significant figures in the answer.
Therefore, from the addition rule, the correct answer is 109.
Answer:
when carbon dioxide is burned they cause pollution
I think it is yes, the reaction may require an activation energy
Answer:
81.5 L
Explanation:
We can use the combined gas law equation that gives the relationship among pressure, temperature and volume of gases for a fixed amount of gas.
P1V1 / T1 = P2V2 / T2
where P1 - pressure, V1 - volume and T1 - temperature at the first instance
P2 - pressure, V2 - volume and T2 - temperature at the second instance
substituting the values in the equation
1240 Torr x 47.2 L / 298 K = 730 Torr x V2 / 303 K
V2 = 81.5 L
the new volume the gas would occupy when the conditions have changed is 81.5 L
When a solution of Pb(NO3)2(aq) is mixed with a solution of KI(aq), a precipitate of PbI₂ will form; K⁺ and NO₃⁻ are spectator ions.
<u>Explanation:</u>
When an aqueous solution of lead nitrate (Pb(NO₃)₂ is mixed with aqueous solution of potassium iodide (KI), then there is a precipitate formation of lead iodide (PbI₂), and the potassium (K⁺) ion and nitrate (NO₃⁻) ion acts as spectator ions that is ions do not involved in the reaction.
The reaction can be represented as,
Pb(NO₃)₂(aq) + 2 KI (aq) → PbI₂(s) + 2KNO₃(aq)
The ionic equation can be written as,
Pb²⁺(aq) + 2 NO₃⁻(aq) + 2 K⁺(aq) + 2 I⁻(aq) → PbI₂(s) + 2K⁺(aq) + 2NO₃⁻(aq)
On both sides of the equation, we have K⁺ and NO₃⁻ ions, which gets cancelled, and these 2 ions are called as spectator ions.