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Questions in chemistry

[Terjawab] The balanced equation for the reaction occurring when calcium nitrate solution is mixed with sodium phosphate solution is: [tex]3 Ca ( NO _3)_2( aq )+2 Na _3 PO _4( aq ) \rightarrow Ca _3( PO _4)_2( aq )+6 NaNO _3( aq )[/tex]. [tex]3 Ca ( NO _3)_2( aq )+2 Na _3 PO _4( aq ) \rightarrow Ca _3( PO _4)_2(s)+6 NaNO _3( aq )[/tex]. [tex]2 Ca ( NO _3)_2( aq )+3 Na _3 PO _4( aq ) \rightarrow 2 Ca _3( PO _4)_2(s)+6 NaNO _3( aq )[/tex]. [tex]3 CaNO _3( aq )+ Na _3 PO _4( aq ) \rightarrow Ca _3 PO _4( aq )+3 NaNO _3(s)[/tex]. [tex]Ca ( NO _3)_2( aq )+2 NaPO _4( aq ) \rightarrow Ca ( PO _4)_2(s)+2 NaNO _3( aq )[/tex].

[Terjawab] Which is a characteristic of mixtures? A. They are chemically bonded together. B. They can be classified as pure substances. C. They have fixed ratios between their components. D. They can be separated by physical processes.

[Terjawab] What is the formula of the ionic compound iron (III) fluoride? A. [tex]Fe _3 F[/tex] B. FeF C. [tex]Fe _3 F_3[/tex] D. [tex]FeF _3[/tex]

[Terjawab] What is the pH of 0.4100 M NaCN? Be sure to use at least 4 significant figures throughout your calculations; you can only be off by 0.1 pH units.

[Terjawab] Write the electronic position in the modern periodic table. On what basis are the group and period separated in the modern periodic table? In which group do Fluorine, Chlorine, and Bromine lie in the periodic table? Which one is more reactive among them? If you are given a chance to make improvements in the modern periodic table, what changes would you make in it? Explain with reasons.

[Terjawab] A sample of an unknown substance has a mass of 0.465 kg. If [tex]$3,000.0 J$[/tex] of heat is required to heat the substance from [tex]$50.0^{\circ} C$[/tex] to [tex]$100.0^{\circ} C$[/tex], what is the specific heat of the substance? Use [tex]$q=m C_p \triangle T$[/tex].

[Terjawab] Which of the following electrolytes would you use to electroplate silver (Ag) on iron (Fe)? A. [tex]$FeSO _4$[/tex] B. [tex]$CuCl _2$[/tex] C. [tex]$AgNO _3$[/tex] D. [tex]$Zn \left( ClO _3\right)_2$[/tex]

[Terjawab] A sample of propane [tex]$\left( C _3 H _8\right)$[/tex] has a mass of 0.47 g. The sample is burned in a bomb calorimeter that has a mass of 1.350 kg and a specific heat of [tex]$5.82 J /\left( g \cdot{ }^{\circ} C \right)$[/tex]. How much energy is released by the reaction if the temperature of the calorimeter rises by [tex]$2.87^{\circ} C$[/tex]? Use [tex]$q=m C_p \Delta T$[/tex].

[Terjawab] The dosage of quinine when a $145-lb$ adult takes a $200.-mg$ tablet is weight. How many $\mu g$ of drug per kg of body? A. 15.2 B. $1.60 \times 10^3$ C. $4.41 \times 10^5$ D. $1.38 \times 10^6$ E. $3.04 \times 10^3$

[Terjawab] Each atom of an element has the following electron configuration: [tex]$1 s^2 2 s^2 2 p^6 3 s^2 3 p^6 4 s^2 3 d^{10} 4 p^6 5 s^2 4 d^{10} 5 p^5$[/tex] What is the name of the element? A. bromine B. iodine C. tellurium D. xenon