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Questions in chemistry

[Terjawab] A student sets up the following equation to solve a problem in solution stoichiometry: [tex]$\left(539 . \frac{mg}{dL}\right)\left(\frac{10^{-3} g}{1 mg}\right)\left(\frac{1 dL}{10^{-1} L}\right)\left(\frac{10^{-3} L}{1 mL}\right)=\text { ? }$[/tex] Enter the units of the student's answer.

[Terjawab] Explain the process of formation of a molecule of ammonia, sodium chloride, and magnesium chloride with figures.

[Terjawab] What volume in $dm^3$ of oxygen at STP is required to convert 60 g of carbon completely into carbon (IV) oxide? $[C = 12, O = 16$, molar volume $= 22.4 dm^3]$

[Terjawab] In the formula [tex]q=\frac{m}{MH}[/tex], where [tex]$q$[/tex] is the amount of substance, [tex]$m$[/tex] is mass, and [tex]$MH$[/tex] is molar mass, how would you solve for mass [tex]$m$[/tex]? a. [tex]$m=MHq$[/tex] b. [tex]$m=\frac{MH}{q}$[/tex] c. [tex]$m=MH-q$[/tex] d. [tex]$m=MH-q$[/tex]

[Terjawab] A student sets up the following equation to solve a problem in solution stoichiometry. (The ? stands for a number the student is going to calculate.) Enter the units of the student's answer. [tex]\frac{(0.27 L)\left(\frac{1 mL}{10^{-3} L}\right)\left(2.07 \frac{g}{mL}\right)}{\left(20.15 \frac{g}{mol}\right)}=? \square[/tex]

[Terjawab] In the formula $q=\frac{m}{M H}$, where $q$ is the amount of substance, $m$ is mass, and MH is molar mass, how would you solve for molar mass $M H$? A. $M H=\frac{q}{m}$ B. $M H=m q$ C. $M H=\frac{m}{q}$ D. $M H=m-q

[Terjawab] What transition energy corresponds to an absorption line at 527 nm? A. $2.65 x 10^{-19} J$ B. $5.69 x 10^{-19} J$ C. $3.77 x 10^{-19} J$ D. $3.26 x 10^{-19} J

[Terjawab] Consider the chemical equations shown here. [tex] \begin{array}{l} 2 H_2(g)+O_2(g) \rightarrow 2 H_2 O(g) \Delta H_1=-483.6 kJ \div 2=-241.8 kJ / mol \\ 3 O_2(g) \rightarrow 2 O_3(g) \Delta H_2=284.6 kJ+2=142.3 kJ / mol \end{array} [/tex] What is the overall enthalpy of reaction for the equation shown below? [tex]$3 H_2(g)+O_3(g) \rightarrow 3 H_2 O(g)$[/tex]

[Terjawab] Consider the following intermediate chemical equations: [tex]$\begin{array}{l} 2 Na(s)+Cl 2(g) \rightarrow 2 NaCl(s) \ 2 Na_2 O(s) \rightarrow 4 Na(s)+O_2(g) \end{array}$[/tex] In the final chemical equation, NaCl and [tex]$O _2$[/tex] are the products that are formed through the reaction between [tex]$Na _2 O$[/tex] and [tex]$Cl _2$[/tex]. Before you can add these intermediate chemical equations, you need to alter them by A. multiplying the second equation by 2. B. multiplying the first equation by 2. C. multiplying the first equation by (1/2). D. multiplying the second equation by (1/4).

[Terjawab] What is the frequency of a photon with an energy of 4.56 $10^{-19} J$? A. $6.42 x 10^{14} Hz$ B. $5.10 x 10^{14} Hz$ C. $6.88 x 10^{14} Hz$ D. $4.36 x 10^{14} Hz