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Questions in chemistry

[Free] Which process is an example of a chemical reaction? A. melting B. boiling C. freezing D. rusting

[Free] En la siguiente reacción: [tex]H_2(g)+Br_2(g) \rightarrow 2HBr[/tex], ¿Qué ocurre con el numero de colisiones cuando se agregan mas moleculas de Bromo?

[Free] Time to Think: Questions 1-4, for this reaction, predict the direction of the shift in equilibrium position that occurs in response to each of the following changes in conditions: [tex]As_4 O_6(s)+6 C(s) \longleftrightarrow As_4(g)+6 CO(g)[/tex] ([tex]As _4 O _6[/tex], is the infamous toxic arsenic compound utilized in old detective stories). 1. The addition of carbon monoxide. 2. The addition of [tex]C ( s )[/tex].

[Free] Calculate the energy of a photon with a wavelength of 680 nm. 1) $3.0 \times 10^{-18} J$ 2) $0.292 \times 10^{-19} J$ 3) $2.92 \times 10^{-19} J$ 4) $29.0 \times 10^{-19} J$

[Free] NaCl has a [tex]$\Delta H_{\text {fus }}=30.2 kJ / mol$[/tex]. What is the mass of a sample of NaCl that needs 732.6 kJ of heat to melt completely? Use [tex]$q=n \Delta H$[/tex].

[Free] Collect data: Beginning with Na, record the number of energy levels, number of protons, and atomic radius for each element in period 3. \begin{tabular}{|c|c|c|c|c|c|c|c|c|} \hline Element & Na & Mg & Al & Si & P & S & Cl & Ar \\ \hline Number of energy levels & & & & & & & & \\ \hline Number of protons & & & & & & & & \\ \hline Atomic radius $( pm )$ & & & & & & & & \\ \hline \end{tabular}

[Free] Which container has gas stored at the highest temperature? 1 2 3 4

[Free] Which of the following is a substance? A) Air B) Saltwater C) Oxygen (O2) D) Trail mix

[Free] The molar heat of fusion for water is $6.01 kJ / mol$. How much energy must be added to a $75.0-g$ block of ice at $0^{\circ} C$ to change it to 75.0 g of liquid water at $0^{\circ} C$? Use $q=n \Delta H$.

[Free] Using complete sentences, explain how to predict the products and balance the reaction between sulfuric acid and potassium hydroxide. [tex]H_2 SO_4+KOH \longrightarrow[/tex]