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Questions in chemistry

[Terjawab] What is the primary purpose of writing a lab report? A. to summarize the rules of the laboratory to the students who will use it B. to communicate the specifics of an experiment that was conducted C. to record observations in an organized format during the experiment D. to record which days a student worked in the laboratory

[Terjawab] How many atoms of each element are in the chemical formula [tex]$Ca ( OH )_2$[/tex]? A. 1 cakium, 1 oxygen, and 1 hydrogen B. 1 cakium, 2 oxygen, and 2 hydrogen C. 2 cakium, 1 oxygen, and 2 hydrogen D. 2 cakium, 2 oxygen, and 2 hydrogen

[Terjawab] The mass number of [tex]$Fe ^{2+}$[/tex] is 56. How many neutrons are there in a single [tex]$Fe ^{2+}$[/tex] atom? A. 28 B. 30 C. 56 D. 58

[Terjawab] Select the correct answer. Vitellium (V) has the following composition: V-188: 187.9122 amu, 10.861% V-191: 190.9047 amu, 12.428% V-193: 192.8938 amu; 76.711% Based on this data, what can you predict about the average atomic mass of vitellium? A. It will be equal to the arithmetic mean of the masses of the three isotopes. B. It will be closer to the mass of Vi-188. C. It will be closer to the mass of V-193. D. It will be equal to the mass of Vi-193.

[Terjawab] Test your understanding of isotopes by selecting the correct relationship between the pair of atoms ${ }_6^{13} C$ A. Same Atom, Not Isotopes of Each Other B. Different Element C. Isotopes

[Terjawab] A 1.8 gram sample of HCl is added to enough water to make 5.5 L of solution. What is the pH of this solution at 25 °C? Be sure to use at least 4 significant figures throughout your calculations; you can only be off by 0.1 pH units. Note: Due to the constraints of Canvas, please assume that all numerical values were given with 4 significant figures.

[Terjawab] Consider the nuclear equation below. ${ }_{94}^{239} Pu \longrightarrow X+{ }_2^4 He$ What is $X$ ? A. ${ }_{96}^{235} Cm$ B. ${ }_{92}^{243} U$ C. ${ }_{92}^{235} U$ D. ${ }_{96}^{243} Cm$

[Terjawab] Which of the following shows a Bronsted-Lowry acid reacting? A. [tex]$CO + NO _2 \rightarrow CO _2+ NO$[/tex] B. [tex]$NH _3+ H ^{+} \rightarrow NH _4{ }^{+}$[/tex] C. [tex]$CO _3^{2-}+ H ^{+} \rightarrow HCO _3^{-}$[/tex] D. [tex]$HCl + H _2 O \rightarrow H _3 O ^{+}+ Cl ^{-}$[/tex]

[Terjawab] The table describes how some substances were formed. | Substance | Description | |---|---| | $P$ | Formed by boiling pure water | | $Q$ | Formed by combining three hydrogen atoms to every nitrogen atom | | $R$ | Formed by adding 5 g of sugar to 1 L of water | | $S$ | Formed by compressing carbon under high pressure | Based on the given descriptions, which substance is most likely a mixture? P Q R S

[Terjawab] When being stored, flammable gases should be separated from each other and from: A. toxic chemicals B. corrosives C. oxidizers D. cryogenic liquids