GuideFoot - Learn Together, Grow Smarter. Logo

Questions in chemistry

📝 Answered - What is K for a reaction if ∆G° = -347.2 kJ/mol at 25.00 °C? Give your answer to four significant figures. (R = 8.314 J/mol·K)

📝 Answered - Four different thermometers were used to measure the temperature of a sample of impure boiling water. The measurements are recorded in the table below. | Thermometer | Temperature Reading 1 | Temperature Reading 2 | Temperature Reading 3 | | :---------- | :-------------------- | :-------------------- | :-------------------- | | W | $100.1^{\circ} C$ | $99.9^{\circ} C$ | $96.9^{\circ} C$ | | X | $100.4^{\circ} C$ | $102.3^{\circ} C$ | $101.4^{\circ} C$ | | Y | $90.0^{\circ} C$ | $95.2^{\circ} C$ | $98.6^{\circ} C$ | | Z | $90.8^{\circ} C$ | $90.6^{\circ} C$ | $90.7^{\circ} C$ | The actual boiling point of pure water is $100.0^{\circ} C$. What can be concluded from the data about the reliability and validity of the thermometers? A. Thermometer $Z$ is the most reliable. B. Thermometer $X$ has the highest validity. C. Thermometer $W$ is the most reliable. D. Thermometer $Y$ has the highest validity.

📝 Answered - QUESTION 1: THERMOCHEMISTRY a) An LP gas tank in a home barbeque contains 13.2 kg of propane, [tex]C _3 H _8[/tex]. Calculate the heat (in kJ ) associated with the complete combustion of all of the propane in the tank. [tex]C_3 H_8(g)+5 O_2(g) \longrightarrow 3 CO_2(g)+4 H_2 O(g) \Delta H_{run}=-2044 kJ[/tex]

📝 Answered - What is the molality of a solution that has 3 mol of glucose in 6 kg of water? A. $\frac{3 mol}{6 L}$ B. $\frac{3 kg}{6 L}$ C. $\frac{3 mol}{6 kg}$ D. $\frac{6 kg}{3 mol}$

📝 Answered - Which classification of matter includes materials that can no longer be identified by their individual properties? A) Element B) Mixture C) Compound D) Atom

📝 Answered - Identify the reactants in the reaction [tex]HCl + NaOH \rightarrow NaCl + H _2 O[/tex]. A. HCl and NaOH B. Na and Cl C. H and Cl D. NaCl and [tex]H _2 O[/tex]

📝 Answered - Which substance has [tex]$\Delta H f$[/tex] defined as [tex]$0 kJ / mol$[/tex] ? [tex]$H _2 O$[/tex] (s) Ne (i) [tex]$F _2(g)$[/tex] [tex]$CO _2(g)$[/tex]

📝 Answered - 3. Petroleum is found in the purest form under the Earth's crust. 4. Oxygen gas is produced when coal burns. 5. Coke is harder and denser than charcoal.

📝 Answered - Select the correct answer. In this reaction, what effect does a change in the concentration of substances have on the reverse reaction rate? [tex]CaCO_3(s) \rightleftharpoons CaO(g)+CO_2(g)[/tex] A. The rate of the reverse reaction increases with an increase in the concentration of [tex]CaCO _3(s)[/tex]. B. The rate of the reverse reaction increases with an increase in the concentration of [tex]CaO (g)[/tex] and [tex]CO _2(g)[/tex]. C. The rate of the reverse reaction decreases with a decrease in the concentration of [tex]CaCO _3(s)[/tex]. D. The rate of the reverse reaction decreases with an increase in the concentration of [tex]CaO (g)[/tex] and [tex]CO _2(g)[/tex] E. The rate of the reverse reaction increases with a decrease in the concentration of [tex]CaO (g)[/tex] and [tex]CO _2(g)[/tex].

📝 Answered - The chemical formula for cesium oxide is $Cs _2 O$. What is the charge of cesium? A. +1 B. +2 C. -1 D. -2