Question

What is the coefficient of H.So, when the following equation is properly balanced with the smallest set of whole numbers? __Cas(PO4h + H2SO4 - Caso + HPO. A) 3 B) 8 C) 10 D) 11 2) What is the coefficient of H20 when the following equation is properly balanced with smallest set of whole numbers? ALC + H2O - AM(OH), + CHE A) 3 B) 4 C) 6 D) 12 E) 24 3) of the reactions below, which one is not a combination reaction? A) C + 02 - CO2 B) 2Mg + 02 - 2MgO C) 2N2 + 3H2 + 2NH3 D) 2CH4 + 402 – 2002 + 4H20 4) How many grams of Ch can be prepared from the reaction of 16.0 g of MnO, and 30.0 g of HCI according to the following chemical equation? MnO, + 4HCI = MnCl + Cl: +2H:0 A) 0.82 g B) 5.8 g C) 13.0 g D) 14.6 g 5) A) B) Which of these compounds is a strong electrolyte? HO 02 H SO: CH20. (glucose) 6) Based on the solubility rules, which one of these compounds should be insoluble in water? A) Na2SO4 B) BaSO4 C) CuSO4 D) MgSO4

Answer 1

Write the reaction as follows: Caz (PO.), +H,50— CaSO+ HỌPO4 Ca balance: There are 3 Ca atoms on left side and 1 Ca on right side. So put 3 before CaSO4 to balance Ca atoms. Ca3(PO4), +H,50 —3CaSO. + H3PO4 Sbalance: There are 3S atoms on right side and 1 S on left side. So put 3 before H2SO4 to balance Satoms. Ca,(PO), + 3H,SO. — 3CaSO. + H2PO. Pbalance: There are 2 atoms on left side and 1P on right side. So put 2 before H2PO, to balance P atom s. Ca(PO4)3 + 3H,504 3CaSO. + 2H2PO4 So the balanced equation is Ca(PO4)3 + 3H,SO4 — 3CaSO. + 2H2PO4 Coefficient of H,SO, is 3. Therefore, the correct option is A. ----------------- (2) Write the reaction as follows: A1, Cz+H20 - Al(OH), + CH. Al balance: There are 4 A1 atoms on left side and 1 Al on right side. So put 4 before Al(OH), to balance A1 atoms. A1.C +H,0 – 4Al(OH), + CH, Cbalance: There are 3C atoms on left side and 1 C on right side. So put 3 before CH, to balance atoms. A1 C3 +,0 4A1(OH), +3CH. H balance: There are 2 H atoms on left side and 24 H atoms on right side. So put 12 before H,O to balance H atoms. A1,Cx+12H,0 – 4Al(OH), +3CH, So the balanced equation is Al. Cz+12H,0 - 4Al(OH), +3CH, Coefficient of H,O is 12. Therefore, the correct option is D. - - - - - - - - - - - - - - - - - - - - - - - - -

Combination reaction: It is type of reaction in which two or more elements or compounds combine to form a single compound A+B — → AB C+03 →CO2 2Mg +0, 2Mgo 2N, +3H, —→ 2NH, the above reactions are in the form of A+B — which are combination type of reactions. AB, But the reaction 2CH, + 40 200, +4H,0 is not combination type of reaction. Therefore, the correct option is D - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - (4) Write the reaction as follows: MnO, +4HC1 —→MnCl2 + Cl2 + 2H,0 mass of MnO, = 16.0 g molar mass of MnO, = 86.9 g/mol moles of MnO, = 16.0gxmol = 0.184 m ol mass of HC1 = 30,0 g molar mass of HCl = 36.5 g/mol moles of HC1 = 30.0gx mas = 0.822 mol - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - From the reaction the stoichiometric relation between MnO, and HClis moles of MnO moles of HCI 1 Substitute the calculated moles in the above relation, the moles with least is the limitig reactant 0.184 mol of MnO 0.822 mol of HCI - - - - - - - - - - - - - - - 0.184 mol of MnO, < 0.2055m ol HșPO. So, the limiting reagent is MnO, ----- -- - Limiting reactant is used to determine the amount of product formed. From the reaction the stoichiometric relation between MnO, and HClis moles of MnO2, moles of Cl, moles of Cl, = moles of MnO, = 0.184 mol molar mass of Cl, = 71 g/mol mass of Cl, = 0.184 mol x 71 g/mol = 13.0g Therefore, the correct option is c