Explanation:
because there are 4 Iodines on the left, we'll put. 4 in front of NaI to balance it. This would result in 4 Na on the left, so we'll put a 2 in front of Sodium Sulfate to balance the right side. Now we have 4 Na and I on both side, as well as 2 Sulfate on both sides. Pb is already balanced. The equation is now complete.
The correct answer is a. This is because the pH of a solution is defined as -log10(concentration of H+ ions). An inverse logarithmic scale such as this means that a solution with a lower concentration of H+ ions will have a higher pH than one with a higher concentration. Therefore we know that the pH of the second sample will be higher than the first.
Since the logarithmic scale has the base 10, a change by 1 on the scale is a consequence of multiplication/division of the H+ concentration by a factor of 10. As the scale is inverse, this means that a decrease of concentration by factor 1000 is equivalent to increasing the pH by (1000/10) = 3.
The mass of CO₂ gas produced during the combustion of one gallon of octane is 8.21 kg.
The given parameters:
- <em>Density of the octane, ρ = 0.703 g/ml</em>
- <em>Volume of octane, v = 3.79 liters</em>
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The mass of the octane burnt is calculated as follows;

The combustion reaction of octane is given as;

From the reaction above:
228.46 g of octane -------------------> 704 g of CO₂ gas
2,664.37 of octane --------------------> ? of CO₂ gas

Thus, the mass of CO₂ gas produced during the combustion of one gallon of octane is 8.21 kg.
Learn more about combustion of organic compounds here: brainly.com/question/13272422
The two elements that have the same properties as sodium are potassium and rubidium .
<h3>What is periodic table?</h3>
The periodic table is an arrangement of the elements in order of increasing atomic number.
From the list, the two elements that have the same properties as sodium are potassium and rubidium .
Proton has an atomic number of 20 and a mass number of 40. The number of electrons is the same as the number of protons. Given that the atomic number is the number of protons present, we have 20 electrons and 20 protons.
Number of neutrons = Mass number - Number of protons
= 40 - 20 = 20 neutrons
Learn more about periodic table:brainly.com/question/11155928
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