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Questions in chemistry

[Terjawab] Which is a characteristic of all matter? A. They are metal B. They have a charge C. They are made of two or more types of atoms. D. They form chemical bonds through electron sharing.

[Terjawab] Use the periodic table to complete each nuclear fusion equation. ${ }_1^2 H +{ }_1^3 H \rightarrow{ }_B^A He$ ${ }_7^{14} N+{ }_1^1 H \rightarrow{ }_D^{ C } E$ A: $\square$ C: $\square$ B: $\square$ D: $\square$ E: $\square$

[Terjawab] What characteristic of CFC refrigerants makes them more likely to reach the stratosphere than most other compounds that contain chlorine? A. CFCs are attracted to the dust in the stratosphere B. CFCs are attracted to the static in the stratosphere C. CFCs that contain chlorine but not hydrogen are so stable that they do not break down in the lower atmosphere D. CFCs are lighter than other damaging compounds making them easier to float upward when released

[Terjawab] The shell having $n=3$ contains how many subshells, how many orbitals, and up to how many electrons? A. 3; 6; 12 B. 2; 4; 8 C. 3; 12; 36 D. 3; 9; 18 E. 3; 6; 18

[Terjawab] $2 Ca+O_2 \rightarrow 2 CaO$ The molar mass of each substance is provided in the table below. | Substance | Molar Mass (g/mol) | | :-------- | :----------------- | | Calcium $( Ca )$ | 40.08 | | Oxygen $\left( O _2\right)$ | 32.00 | | Calcium oxide $( CaO )$ | 56.08 | What mass of calcium is needed? $4.25 mol O _2$ $\square$ 2 $\square$ mol Ca 40.1 g Ca $=$ $\square$ g Ca 1 $mol O _2$ 1 mol Ca

[Terjawab] 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 $\Delta H_{\text {nan }}=\sum\left(\Delta H_{\text {f, products }}\right)-\sum\left(\Delta H_{\text {f, reectants }}\right)$. A. -3,572.1 kJ B. -1,267.2 kJ C. 1,267.2 kJ D. 3,572.1 kJ

[Terjawab] Consider the following intermediate reactions: [tex] \begin{array}{ll} CH_4(g)+2 O_2(g) \rightarrow CO_2(g)+2 H_2 O(g) & \Delta H_1=-802 kJ \\ 2 H_2 O(g) \rightarrow 2 H_2 O(l) & \Delta H_2=-88 kJ \end{array} [/tex] The overall chemical reaction is as follows: [tex]CH_4(g)+2 O_2(g) \rightarrow CO_2(g)+2 H_2 O(l) \quad \Delta H_2=-890 kJ[/tex] What is the correct enthalpy diagram using Hess's law for this system? [tex]CH_2(a)+2 O_2(g)[/tex]

[Terjawab] Calculate the enthalpy of each reaction per mole of reactant using the formula below, which also converts joules to kilojoules. Record to 2 significant figures. $\Delta H=\frac{-q}{\text { moles }} * \frac{k J}{1000 J}$ Reaction 1: $\square$ $kJ / mol$ Reaction 2: $\square$ $kJ / mol$

[Terjawab] Show the ions produced as each of the following salt molecules ionizes in body fluids: sodium chloride, potassium chloride, calcium chloride, magnesium chloride, and calcium carbonate.

[Terjawab] How many moles of oxygen must be placed in a 3.00 L container to exert a pressure of 2.00 atm at [tex]$25.0^{\circ} C$[/tex]? Formula: [tex]$P V=n R T(R=0.0821 L \cdot atm / mol \cdot K )$[/tex] Which variables are given? pressure volume temperature moles