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Questions in chemistry

[Answered] An electric device delivers a current of [tex]$15.0 A$[/tex] for 30 seconds. How many electrons flow through it?

[Answered] (1) Write the electronic configuration of an element with atomic mass of 17. (2) What will be the electronic configuration of the following positive charge ions: [tex]$K ^{+}, Cl ^{2+}, Al ^{3+}$[/tex]? (3) What will be the electronic configuration of the following negatively charge ions: [tex]$Cl ^{-}, I ^{-}, Br ^{-}, O ^{2-}$[/tex]?

[Answered] Carbon reacts with oxygen to produce carbon dioxide ([tex]CO_2(g), \Delta H_{f }=-393.5 kJ / mol$[/tex]) according to the equation below. [tex]C(s)+2 O_2(g) \rightarrow CO_2(g)$[/tex] What is the enthalpy change of the reaction? Use [tex]\Delta H_{\text {rxn }}=\sum(\Delta H_{\text {f, products }})-\sum(\Delta H_{\text {f, reactants }})$[/tex]. A. -393.5 kJ B. -196.8 kJ C. 196.8 kJ D. 393.5 kJ

[Answered] Formulate an investigative question. By the end of this lab, you will determine whether you should add cocoa mix (a solid) before or after heating water (liquid) to make hot chocolate. State a broad question about solubility whose answer would help you determine this.

[Answered] Information on hazards associated with a particular solvent can be obtained A. by asking your coworkers B. from the project specifications C. by calling the store where you bought it D. from the SDS for that product

[Answered] Directions: 1. Look around your house and find 2 examples of each state of matter: solid, liquid, and gas. 2. List them in the correct column in the table below. 3. Write what you observed that helped you decide the state of matter for each item. | State of Matter | Example from Home | What I Observed | |---|---|---| | Solid | 1. 2. | | | Liquid | 1. 2. | | | Gas | 1. 2. | |

[Answered] Through chemical weathering, even hard rocks can produce what? A. sediment B. limestone C. kaolin D. minerals

[Answered] 3. In one molal solution that contains 0.5 mol of solute, there is (A) 500 g of solvent (B) 100 mL of solvent (C) 1000 g of solvent (D) 500 mL of solvent 4. The mixture that forms maximum boiling azeotrope at a specific composition is (A) Water + Nitric acid (B) Ethanol + water

[Answered] Ammonia $\left( NH _3(g), \Delta H_{ f }=-45.9 kJ / mol \right)$ reacts with oxygen to produce nitrogen and water $\left( H _2 O ( g ), \Delta H_{ f }=-241.8\right.$ $kJ / mol$ ) according to the equation below. $4 NH_3(g)+3 O_2(g) \rightarrow 2 N_2(g)+6 H_2 O(g)$ What is the enthalpy of the reaction? Use $\Delta H_{\text {rxn }}=\sum\left(\Delta H_{\text {f,products }}\right)-\sum\left(\Delta H_{f, \text { reactants }}\right)$. A. -3,572.1 kJ B. -1,267.2 kJ C. 1,267.2 kJ D. 3,572.1 kJ

[Answered] | Name of People/Scientist | Element's Name | Symbol | |---|---|---| | 1. Neils Bohr | Bohrium | Bh | | 2. Albert Einstein | Einsteinium | Es | | 3. Ernest Lawrence | Lawrencium | Lr | | 4. Glenn T. Seaborg | Seaborgium | Sg | | 5. Dmitri Mendeleev | Mendelevium | Md | | 6. Marie and Pierre Curie | Curium | Cm | | 7. Enrico Fermi | Fermium | Fm | | 8. Ernest Rutherford | Rutherfordium | Rf | | 9. Alfred Nobel | Nobelium | No | | 10. Nicolas Copernicus | Copernicium | Cn |