Questions in chemistry

Questions in chemistry

📝 Answered - I need help please this is orgo 2 please answer must be right

📝 Answered - Identify the oxidation state of H in [tex]H _2(g)[/tex]. [tex]Mg ( s )+2 HBr ( aq ) \rightarrow MgBr _2( aq )+ H _2(g)[/tex] A. +1 B. -1 C. 0 D. +2 E. -2

📝 Answered - Which equation has both a liquid and a gas as products? [tex]2 HgO ( s ) \rightarrow 2 Hg ( l )+ O _2(g)[/tex] [tex]2 Mg ( s )+ O _2(g) \rightarrow 2 MgO ( s )[/tex] [tex]2 KClO _8(s) \rightarrow 2 KCl ( s )+3 O _2(g)[/tex] [tex]Mg ( s )+2 HCl ( aq ) \rightarrow H _2(g)+ MgCl _2( aq )[/tex]

📝 Answered - A. Unscramble the letters to form action words that may result in physical change in matter. 1. UTC 2. ZESUEQE 3. OCHP 4. IESLC 5. CSHUR 6. ESHVA 7. MEHARM 8. SERSP 9. RATE 10. ENBD

📝 Answered - Select the correct answer. Excess sodium hydroxide is added to a solution containing 4.6 grams of magnesium chloride. A reaction takes place according to this equation: [tex]2 NaOH(aq)+MgCl_2(aq) \rightarrow 2 NaCl(aq)+Mg(OH)_2(s)[/tex] The magnesium hydroxide produced by the reaction was collected and weighed. If the mass of the magnesium hydroxide was 2.7 grams, what was the percent yield? Use the periodic table. A. [tex]48 \%[/tex] B. [tex]59 \%[/tex] C. [tex]61 \%[/tex] D. [tex]96 \%[/tex]

📝 Answered - What is the conjugate base that is formed when carbonic acid is dissolved in water? A. $H _3 O ^{+}$ B. $HCO _3^{-}$ C. $CO _3{ }^{2-}$

📝 Answered - Which chemical equation is unbalanced? [tex]$C + O _2 \rightarrow CO _2$[/tex] [tex]$Sr + O _2 \rightarrow 2 SrO$[/tex] [tex]$6 H _2+3 O _2 \rightarrow 6 H _2 O$[/tex] [tex]$H _2+ H _2+ O _2 \rightarrow H _2 O + H _2 O$[/tex]

📝 Answered - d. What are sub-atomic particles? Write down their position in an atom. e. What is meant by the atomic mass of an atom? Write down the atomic mass of oxygen, sodium, aluminium, and argon. f. Define atomic number and atomic weight. g. What is 2n² rule? Calculate the maximum number of electrons found in shell N by using this rule. h. What is valency? Write down the valency of oxygen, magnesium, and calcium. i. What are valence electrons? Write with an example. j. What is duplet and octet state? Describe with an example of each. k. What is molecular formula? Write down the method of writing molecular formula. l. What is molecular weight? How does it differ from atomic weight?

📝 Answered - Compound A has 12 g of carbon combining with 16 g of oxygen. Compound B has 12 g of carbon combining with 32 g of oxygen. What is the simplest ratio of oxygen masses in both compounds? A. 1:2 B. 2:1 C. 3:2 D. 4:3

📝 Answered - What is the mass of $1.450 mol Cd _3 N_2$? A. 124.2 g B. 234.7 g C. 529.6 g D. 738.9 g

« Prev
1
...
140
141
142
143
144
...
284
Next »