Pt.4 Chemistry Ch. 1 Questions

Service Description

just two main Questions and then some terms to finish. 26. The energy of a system can be (A) easily changed to mass (B) transformed into a different form (C) measured only as potential energy (D)measured only as kinetic energy ans. 26. (B) Energy can change form. Examples include light to heat and heat to electrical. 27. If the triangle H of a reaction is a negative quantity, the reaction is definitely (A) endothermic (B) unstable (C) exothermic (D) reversible ans. 27. When the heat of reaction (a triangle H) is negative, the system is losing energy. When a system loses energy, the process is referred to as 'exothermic.' In the following list, write E for the 'elements', C for the 'compounds', M for the 'mixtures'. 28. Water 29. Wine 30. Soil 31, Silver 32. Aluminum oxide 33. Hydrogen 34. Carbon dioxide 35. Air 36. Hydrochloric acid 27. Nitrogen 38. Tin 39. Potassium chloride ans. 28. (C)compound- 'water' is a chemical reaction of hydrogen and oxygen in a particular ratio. 29. (M) mixture- 'Wine' is a physical blend of many compounds and can be easily separated. 30. (M) 'mixture'-"Soil' is a physical blend of many and can be easily separated. 31. (E) element- 'Silver' cannot be decomposed by ordinary chemical means. 32. (C) 'compound'- 'Aluminum oxide' is a chemical blend of aluminum and oxygen in a particular ratio; 33 (E) element-Hydrogen cannot be decomposed by ordinary chemical means; 34, (C)'compound'- 'Carbon dioxide' is a chemical blend of 'carbon' and 'oxygen' in a particular ratio; 35. (M) 'mixture'-'Air' is a 'physical blend' of many 'gases' ('nitrogen' and 'oxygen' primarily) and can be easily separated; 36. (C) "compound"-'Hydrochloric acid' is the compound 'hydrogen chloride' (generally in a water solution). The best answer is "compound" if you choose to focus on only the hydrogen chloride. The best answer is "mixture" if you choose to look at the hydrochloric acid as a solution. 37. (E) an 'element'; 'Nitrogen' cannot be decomposed by ordinary chemical means. 38. (E) an 'element' 'Tin ' cannot be decomposed by ordinary chemical means. 39. (C) 'compound' 'Potassium chloride' is a chemical blend of potassium and chlorine in a particular ratio.