<em>Q=mcΔT</em>
<em>Q=15.2g(0.397</em><span><em>J/g C)(40.3-21)</em>
<em>Q=</em><u>116.5J</u></span>
Au :)
Pb + Cu(2+)---> Pb(2+) + Cu
Mg + Cu(2+)---> Mg(2+) + Cu
2Na + Cu(2+) ---> 2Na(+) + Cu
Au + Cu(2+) ---> (this reaction is not possible)
Answer:
The correct answer is - alpha particle and positron.
Explanation:
In this question, it is given that, 38^88Sr decays to 34^84Kr, which means there is an atomic number decrease by 4, 38 to 34, and atomic mass decreases by 4 as well 88 to 84.
A decrease in the atomic mass is possible only when there is an emission of the alpha particle as an alpha particle is made of 2 protons and 2 neutrons. If an atom emits an alpha particle, there is a change in atomic number as it decreases by two, and its mass number decreases by four.
So after the emission of an alpha particle, the new atom would be
38^88Sr=> 36^84X => 34^84Kr
so there is also two positron emission that leads to decrease in atomic number by one with each emission:
38^88Sr=> 2^4He+ 36^84X => 36^84X + 2(1^0β+) => 34^84Kr
Positron decay is the conversion of a proton into a neutron with the emission of a positron that causes the atomic number is decreased by one, which causes a change in the elemental identity of the daughter isotope.
The correct answer is 3.4 moles of sulfuric acid (H₂SO₄) are needed to react completely with 6.8 moles of lithium hydroxide.
2LiOH + H₂SO₄ → Li₂SO₄ + 2H₂O
The given chemical equation is balanced.
By using stoichiometry, one can witness the following:
2 moles of LiOH requires 1 mole of H₂SO₄
So, 6.8 moles of LiOH requires (1/2) × 6.8 = 3.4 moles of H₂SO₄
