Chemistry Questions & Answers

The density of \( \mathrm{SO}_{2} \) and \( \mathrm{CO}_{2} \) are \( 2.9 \mathrm{~g} / \mathrm{dm}^{3} \) and \( 1.98 \mathrm{~g} / \mathrm{dm}^{3} \) respectively. How much faster does \( \mathrm{CO}_{2} \) diffuse through a porous pot?

Nếu một mẫu chất phóng xạ bắt đầu với 100g và giảm đi 12.5% mỗi giờ, tính khối lượng còn lại sau 4 giờ.

Es el nombre correcto del compues \( \mathrm{CH}_{5}-\mathrm{CH}_{2}-\mathrm{C} \equiv \mathrm{C}-\mathrm{C} \equiv \mathrm{C}-\mathrm{C} \) a. \( 3,5,7 \) decatrino b. \( 3,5,7 \) decino c. \( 4,6,8 \) decino d. \( 4,6,8 \) decatrino

Question B 2 The following redox reaction is used in acidic solution in the Breathalyzer test to determine the level of alcohol in th blood of drunk drivers: \[ \mathrm{H}^{+}(\mathrm{aq})+\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(\mathrm{aq})+\mathrm{C}_{2} \mathrm{H}_{5} \rightarrow \mathrm{Cr}^{3+}(\mathrm{aq})+\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O} \] a) Identify the elements undergoing changes in oxidation state and indicate the initial and final oxidation numbers for theseelements.

Question B2 The following redox reaction is used in acidic solution in the Breathalyzer test to determine the level of alcohol in tl] blood of drunk drivers: \[ \mathrm{H}^{+}(\mathrm{aq})+\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}(\mathrm{aq})+\mathrm{C}_{2} \mathrm{H}_{5} \rightarrow \mathrm{Cr}^{3+}(\mathrm{aq})+\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}(\mathrm{aq})+\mathrm{H}_{2} \mathrm{O} \] a) Identify the elements undergoing changes in oxidation state and indicate the initial and final oxidation numbers for these elements. [5] b) Write and balance the oxidation half-reaction.[6] c) Write and balance the reduction half reaction.[6] d) Combine the half-reactions to produce a balanced redox reaction. [3]

Select the single best answer. Which of the following describes the bonding in the hydrogen cyanide molecule, HCN? As N is \( s p \)-hybridized. C uses \( s p \) hybridized orbitals in bonding. C uses \( s p^{2} \) hybridized orbitals in bonding. C uses \( s p^{3} \) hybridized orbitals in bonding. C uses \( s p^{3} d \) hybridized orbitals in bonding.

(a) \( \mathrm{SiBr}_{4} \) tristorted tetrahedron (b) \( \mathrm{CS}_{2} \) trigonal pyramidal trigonal planar trigonal pyramidal (c) \( \mathrm{NO}_{3}^{-} \) trigonal planar bent trigonal pyramidal tetrahedral to

Select the single best answer. Select the statement that correctly describes the hybridization of phosphorus in \( \mathrm{PF}_{5} \). Phosphorus is \( s p^{2} \) hybridized. Phosphorus is \( s p^{3} \) hybridized. Phosphorus is \( s p^{3} d \) hybridized. Phosphorus is \( s p^{3} d^{2} \) hybridized.

When 200 g of nugar is dissolved in 60.0 g of water, the percent by mass of sugar in the solution is

What is the Structural Formular for water?