19. find the reactants mass in grams using the following reaction.\niron metal reacts in moist air causing…

19. find the reactants mass in grams using the following reaction.\niron metal reacts in moist air causing oxidation and forms iron oxide. this does not protect the iron surface so further reaction continues to occur, and flakes off causing more iron metal to oxidize. this process is called rusting. using the following reaction find the mass of iron before it reacts with oxygen.\n____grams of iron + 96 grams of oxygen → 316 grams of iron oxide\n20.) methane (ch4) reacts with oxygen (o2) and forms carbon dioxide (co2) and water (h2o). which equation below accurately represents this equation?\na. ch4 + 2o2 → co2 + h2o\nb. 2ch4 + o2 → 2co2 + h2o\nc. ch4 + 2o2 → co2 + 2h2o\nd. 2ch4 + 2o2 → co2 + 2h2o\n21.) which equation below accurately represents the formation of magensium oxide?\na. mg + 2o2 → 2mgo\nb. mg + o2 → 2mgo\nc. 2mg + o2 → mgo\nd. 2mg + o2 → 2mgo\n22.) propane reacts with oxygen to form carbon dioxide and water, which equation below accurately represents this reaction.?\na. 2c3h8 + 5o2 → c3o2 + 4h2o\nb. c3h8 + 5o2 → 3co2 + 4h2o\nc. 2c3h8 + 7o2 → 4co2 + 3h2o\nd. c3h8 + 7o2 → 4co2 + 3h2o

19. find the reactants mass in grams using the following reaction.\niron metal reacts in moist air causing oxidation and forms iron oxide. this does not protect the iron surface so further reaction continues to occur, and flakes off causing more iron metal to oxidize. this process is called rusting. using the following reaction find the mass of iron before it reacts with oxygen.\n____grams of iron + 96 grams of oxygen → 316 grams of iron oxide\n20.) methane (ch4) reacts with oxygen (o2) and forms carbon dioxide (co2) and water (h2o). which equation below accurately represents this equation?\na. ch4 + 2o2 → co2 + h2o\nb. 2ch4 + o2 → 2co2 + h2o\nc. ch4 + 2o2 → co2 + 2h2o\nd. 2ch4 + 2o2 → co2 + 2h2o\n21.) which equation below accurately represents the formation of magensium oxide?\na. mg + 2o2 → 2mgo\nb. mg + o2 → 2mgo\nc. 2mg + o2 → mgo\nd. 2mg + o2 → 2mgo\n22.) propane reacts with oxygen to form carbon dioxide and water, which equation below accurately represents this reaction.?\na. 2c3h8 + 5o2 → c3o2 + 4h2o\nb. c3h8 + 5o2 → 3co2 + 4h2o\nc. 2c3h8 + 7o2 → 4co2 + 3h2o\nd. c3h8 + 7o2 → 4co2 + 3h2o

Answer

19.

Explanation:

Step1: Apply law of conservation of mass

According to the law of conservation of mass, the total mass of reactants equals the total mass of products. Let the mass of iron be $x$ grams. The equation is $x + 96=316$.

Step2: Solve for $x$

Subtract 96 from both sides of the equation: $x=316 - 96$.

Answer:

220

20.

Explanation:

Balance the chemical - equation for the combustion of methane. For the reaction of methane ($CH_4$) with oxygen ($O_2$) to form carbon dioxide ($CO_2$) and water ($H_2O$), we need to ensure that the number of each type of atom is the same on both sides of the equation. $CH_4+2O_2\rightarrow CO_2 + 2H_2O$ has 1 carbon atom, 4 hydrogen atoms, and 4 oxygen atoms on both sides.

Answer:

C. $CH_4 + 2O_2\rightarrow CO_2+2H_2O$

21.

Explanation:

Balance the equation for the formation of magnesium oxide. Magnesium ($Mg$) reacts with oxygen ($O_2$) to form magnesium oxide ($MgO$). We need 2 moles of magnesium to react with 1 mole of oxygen to form 2 moles of magnesium oxide to balance the atoms. $2Mg+O_2\rightarrow 2MgO$ has 2 magnesium atoms and 2 oxygen atoms on both sides.

Answer:

D. $2Mg + O_2\rightarrow 2MgO$

22.

Explanation:

Balance the equation for the combustion of propane ($C_3H_8$) with oxygen ($O_2$) to form carbon dioxide ($CO_2$) and water ($H_2O$). $C_3H_8+5O_2\rightarrow 3CO_2 + 4H_2O$ has 3 carbon atoms, 8 hydrogen atoms, and 10 oxygen atoms on both sides.

Answer:

B. $C_3H_8+5O_2\rightarrow 3CO_2 + 4H_2O$