IdeasCuriosas - Every Question Deserves an Answer Logo

Questions in chemistry

[Answered] In which of the following groups do the elements belong to the same period? a) hydrogen, fluorine, and neon b) lithium, sodium, and potassium c) potassium, titanium, and arsenic d) beryllium, carbon, and sulfur

[Answered] Consider the equations below. (1) [tex]$Fe _2 O _3(s) \rightarrow 2 Fe ( s )+\frac{3}{2} O _2(g)$[/tex] (2) [tex]$Fe _2 O _3(s)+3 CO ( g ) \rightarrow 2 Fe ( s )+3 CO _2(g)$[/tex] Which equation must be added to equation (1) to produce equation (2)? A. [tex]$CO ( g )+\frac{1}{2} O _2(g) \rightarrow CO _2(g)$[/tex] B. [tex]$3 CO _2(g) \rightarrow 3 CO ( g )+\frac{3}{2} O _2(g)$[/tex] C. [tex]$3 CO ( g )+\frac{3}{2} O _2(g) \rightarrow 3 CO _2(g)$[/tex]

[Answered] What electron could have quantum numbers [tex]$n=4, l=2, m l$[/tex] [tex]$=-2, m_S=-\frac{1}{2}$[/tex] ? A. A 4d electron B. A [tex]$4 p$[/tex] electron C. A [tex]$4 s$[/tex] electron D. A [tex]$4 f$[/tex] electron

[Answered] Select the correct answer. If 155 grams of potassium (K) reacts with 122 grams of potassium nitrate ($KNO_3$), what is the limiting reagent? $2 KNO_3+10 K \rightarrow 6 K_2 O+N_2$ A. potassium nitrate $(KNO_3)$ B. potassium (K) C. potassium oxide $(K_2 O)$ D. $(N_2)$ E. nitrate $(NO_3)$

[Answered] Which of the following is an example of matter undergoing only a physical change? a) carbon (solid) being burnt in air to form carbon dioxide (a gas) b) hydrogen (gas) forming water with oxygen (gas) c) water (liquid) forming steam (gas) after being heated d) chlorine (gas) forming hydrogen chloride (liquid)

[Answered] Explain the causes of eutrophication

[Answered] Select the correct answer. In the following reaction, how many liters of oxygen will react with 270 liters of ethene [tex]$\left( C _2 H _4\right)$[/tex] at STP? [tex]$C_2 H_{4(g)}+3 O_{2(g)} \rightarrow 2 CO_{2(g)}+2 H_2 O_{(g)}$[/tex] The volume of one mole of gas at STP is 22.4 liters. A. 810 liters B. 135 liters C. 90 liters D. 540 liters

[Answered] In an exothermic reaction, what happens to the surroundings? A. The thermal capacitance is increased. B. The activation energy is restored. C. The temperature increases. D. The temperature decreases.

[Answered] What is the second quantum number of a [tex]$2 s^2$[/tex] electron in phosphorus, [tex]$1 s^2 2 s^2 2 p^6 3 s^2 3 p^3$[/tex]? A. [tex]$I=3$[/tex] B. [tex]$I=0$[/tex] C. [tex]$I=1$[/tex] D. [tex]$1=2$[/tex]

[Answered] Which solution of gas dissolved in water can contain the most gas molecules?