Answer:
298.15 K.
Explanation:
Room temperature is generally taken to be 25 °C (around 77 °F). 0 °C is equivalent to 273.15 K, so we add 273.15 to 25 to find that room temperature is around 298.15 K
The reaction corresponds to the combustion of propane (C3H8). The balanced reaction is:
C3H8(g) + 5O2(g) → 3CO2(g) + 4H2O(g)
The reaction enthalpy is given as:
ΔHrxn = ∑nΔH°f(products) - ∑ nΔH°f(reactants)
= [3ΔH°f(CO2(g)) + 4ΔH°f(H2O(g)] - [1ΔH°f(C3H8(g)) + 5ΔH°f(O2(g)]
= [3(-393.5) + 4(-241.8)] - [-103.9 + 5(0)] = -2043.8 kJ
The enthalpy for the combustion of propane is -2044 kJ
It is not a pure substance, because a solution are mixed chemicals in a way that the molecules are not bonded with one another. Thus, separating them from compounds and elements, which are pure substances.
Answer:
<u>Molar</u><u> </u><u>mass</u><u> </u><u>of</u><u> </u><u>the</u><u> </u><u>unknown</u><u> </u><u>acid</u><u> </u><u>is</u><u> </u><u>7</u><u>9</u><u> </u><u>grams</u>
Explanation:
We have to first get moles in 15.0 ml of sodium hydroxide solution:

since mole ratio of acid : base is 1 : 1, so;
moles of acid that reacted is <u>0</u><u>.</u><u>0</u><u>0</u><u>3</u><u>1</u><u>5</u><u> </u><u>m</u><u>o</u><u>l</u><u>e</u><u>s</u><u> </u><u>o</u><u>f</u><u> </u><u>t</u><u>h</u><u>e</u><u> </u><u>u</u><u>n</u><u>k</u><u>n</u><u>o</u><u>w</u><u>n</u><u> </u><u>a</u><u>c</u><u>i</u><u>d</u><u>.</u>
then we've to get molar mass:
