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Questions in chemistry

[Terjawab] In the reaction $MgCl _2+2 KOH \rightarrow Mg ( OH )_2+2 KCl$, if 3 moles $MgCl _2$ are added to 4 moles KOH, what determines how much $Mg ( OH )_2$ is made? A. The amount of KOH B. The amount of KCl C. The amount of $MgCl _2+ KOH$ D. The amount of $MgCl _2$

[Terjawab] Determine the number of valence electrons in an argon atom.

[Terjawab] Type the correct answer in the box. Round your answer to the nearest hundredth. Element $X$ has two isotopes. The table gives information about these isotopes. | Isotope | Atomic Mass (amu) | Abundance (%) | |---|---|---| | $X-63$ | 62.9296 | 69.15 | | $X-65$ | 64.9278 | 30.85 | The average atomic mass of element $X$ is $\square$ amu.

[Terjawab] Given the following table: | color | dull gray | | ------------------- | ------------------------------ | | density | $11.3 g / cm ^3$ | | volume of sample | $3.00 cm^3$ | | melting point | $327^{\circ} C$ | | reaction with air | lead oxide forms on the surface | | electrical conductivity | conducts some electricity | Which statement is true with respect to the investigation? A. The student investigated only the physical properties of lead. B. The student investigated only the chemical properties of lead. C. The student investigated more physical properties than chemical properties of lead. D. The student investigated more chemical properties than physical properties of lead.

[Terjawab] Which of the following factors most directly contributes to the polarity of water? A. Uneven shape B. Overall abundance C. Large size D. High mass

[Terjawab] Will magnesium and fluorine atoms most likely form an ionic bond or a covalent bond? Write the name and formula of the compound made of magnesium and fluorine.

[Terjawab] Which of the following sets of quantum numbers describe valid orbitals? Check all that apply. [tex]$n=1, l=0, m=0$[/tex] [tex]$n=2, l=1, m=3$[/tex] [tex]$n=2, I=2, m=2$[/tex] [tex]$n=3, l=0, m=0$[/tex] [tex]$n=5, l=4, m=-3$[/tex] [tex]$n=4, l=-2, m=2$[/tex]

[Terjawab] The equation shows a neutralization reaction. [tex]H_2 SO_4+2 NaOH \rightarrow Na_2 SO_4+2 H_2 O[/tex] What is [tex]Na _2 SO _4[/tex]? A. an acid B. a base C. a salt D. an ion

[Terjawab] Which statement best describes the relationship between activation energy and rate of reaction? A. Increasing the activation energy can increase the rate of a reaction. B. Reducing the activation energy can increase the rate of a reaction. C. Increasing the reaction energy does not alter the rate of reaction. D. Reducing the activation energy can decrease the rate of a reaction.

[Terjawab] What happens to a substance at critical temperatures? A) The substance can't change its state, only its temperature. B) The substance changes its state only if it gains thermal energy. C) The substance can't lose any more thermal energy. D) The substance changes its state if it continues gaining or losing thermal energy.