1.Products of most combustion reactions are:
Carbon dioxide and water
2.Alloys are made by melting and combining metals together.
Chemical changes involve electrons,in this process no electron is used/shared or given.
Thus,its not a chemical change.
Answer:
3.336.
Explanation:
<em>Herein, the no. of millimoles of the acid (HCOOH) is more than that of the base (NaOH).</em>
<em />
So, <em>concentration of excess acid = [(NV)acid - (NV)base]/V total</em> = [(30.0 mL)(0.1 M) - (29.3 mL)(0.1 M)]/(59.3 mL) = <em>1.18 x 10⁻³ M.</em>
<em></em>
<em> For weak acids; [H⁺] = √Ka.C</em> = √(1.8 x 10⁻⁴)(1.18 x 10⁻³ M) = <em>4.61 x 10⁻⁴ M.</em>
∵ pH = - log[H⁺].
<em>∴ pH = - log(4.61 x 10⁻⁴) = 3.336.</em>
<span>Well, to start with, since the atomic radius of the gas increases as it goes down the period, it causes there to be a decrease in the effect that the nucleus's positive charge has on the valence electrons ( more electrons in between, and more distance ). This causes the valence electrons to become less tightly bound to the atom, which translates to a deviation from the noble gases tendencies to remain nonreactive.</span>
