The acid-base chemistry reaction of barium hydroxide (Ba(OH)2) with ammonium thiocyanate (NH4SCN) in water creates barium thiocyanate, ammonia, and water. The reaction is highly favorable, but is also so endothermic that the solutions cools to such an extent that a layer of frost forms on the reaction vessel. Explain how an endothermic reaction can be favorable.

Because carbon and silicon are both elements in group 14 on the periodic table, we expect them to react with other elements in similar ways. To some extent, they do, but in some cases, carbon and silicon compounds that seem to have analogous structures have very different chemical characteristics. For example, carbon tetrachloride, CCl4, is very stable in the presence of water, but silicon tetrachloride, SiCl4, reacts quickly with water. The unbalanced equation for this reaction is SiCl4 + H2O → Si(OH)4 + HCl Balance this equation. Write a conversion factor that could be used to convert between moles of SiCl4 and moles of H2O. How many moles of SiCl4 react with 24 moles of water? Write a conversion factor that could be used to convert between moles of Si(OH)4 and moles of water. How many moles of Si(OH)4 form when 4.01 moles of H2O react with an excess of SiCl4?

An increase in water temperature is observed when 1.97 g of NaOH is added. The enthalpy change for this reaction is -2.19 kJ. Calculate the AH°scln for NaOH. The AH°scln for NAOH is -44.5 kJ/mol. The AH° soln for NaOH is -26.3 kJ/mol. O The AH°scln for NaOH is -72.4 kJ/mol.

Write the equilibrium constant expression, K, for the following reaction taking place in dilute aqueous solution.ClO- (aq) + H2O (l)HClO (aq) + OH- (aq)

4. Write the overall and net ionic reactions for the neutralization of H2SO4 by KOH. Why are heats of neutralization often expressed in kJ/mole H2O?

Ancient Romans built often out of bricks and mortar. A key ingredient in their mortar was quicklime (calcium oxide), which they produced by roasting limestone (calcium carbonate). 1. Write a balanced chemical equation, including physical state symbols, for the O-0 decomposition of solid calcium carbonate (CaCO3) into solid calcium oxide and gaseous carbon dioxide. x10 Ar 2. Suppose 86.0L of carbon dioxide gas are produced by this reaction, at a temperature of 230.0 °C and pressure of exactly 1 atm. Calculate the mass of calcium carbonate that must have reacted. Be sure your answer has the correct number of significant digits.

Write the chemical formual of acid: Cl-(aq0+HS04-(aq)  HCI(AQ+SO42-(aq)

Assuming reaction 1 has a enthalpy of 34.52 kJ/mol and reaction two has a enthalpy of 57.6 kJ/mol Calculate the change in enthalpy for the reaction below NaOH(s) + H+(AQ) -> H2O(I) + Na+(AQ) Delta H =

Ammonia is an important chemical used in the production of fertilizer. Industrial production of ammonia from atmospheric nitrogen is difficult because of the energy required to cleave the N-N triple bond. Consider the balanced reaction of ammonia: N2(g) + 3H2(g) → 2 NH3 (9). This reaction has a value of K = 4.3 x 10-2 at 25 °C. Part A Estimate the AH for this reaction using bond energies. Bond Bond Dissociation Energy kcal/mol (kJ/mol) N-H 93 (391) N-N 38 (160) H-H 103 (432) N = N 226 (946) Express your answer as an integer. ΜΕ ΑΣΦ ? kJ/mol

Chemistry Br OH OH Pd catalyst, base (d) "Den Br OR OR Pd catalyst, base