VincenTragosta - Tanya, Jawab, dan Belajar Tanpa Batas Logo

Questions in chemistry

[Terjawab] What ability did the PFAS-containing sandwich wrappers have? A. Grease repelling B. Biodegradability C. Waterproofing D. Heat resistance

[Terjawab] Write T for True and F for False statements. Melamine and Bakelite are examples of thermoplastics. Plastics are soluble in water. PET is used for making sanitary fittings. The harmful effects associated with plastic disposal are reducing the usage of plastics.

[Terjawab] What is the basic unit of matter? A. atom B. molecule C. gas D. compound

[Terjawab] The main acid in the stomach is hydrochloric acid $(HCl)$. Which chemical equations show a reaction that occurs when someone takes an antacid? Check all that apply. $HCl + NaOH \rightarrow NaCl + H_2O$ $2 HCl + CaCO_3 \rightarrow CaCl_2+ CO_2+ H_2O$ $2 HCl + Mg(OH)_2 \rightarrow MgCl_2+2 H_2O$ $6 HCl +2 Al \rightarrow 2 AlCl_3+3 H_2$ $HCl + NaHCO_3 \rightarrow NaCl + H_2O + CO_2$

[Terjawab] Which of the following is green in colour? A) Mn2O7 B) PbCrO4 C) Ag2CrO4 D) K2Cr2O7

[Terjawab] State four effects of petrochemicals on the environment.

[Terjawab] One isotope of sodium has 11 protons and 7 neutrons. What is the mass number of this isotope? A. 4 B. 7 C. 11 D. 18

[Terjawab] Which statement is usually true about the relationship between activation energy and reaction rates? A. Low activation energy barriers result in low rates. B. High activation energy barriers result in low rates. C. Low activation energy barriers result in no reaction. D. High activation energy barriers result in no reaction.

[Terjawab] The equation for the pH of a substance is [tex]$pH = -\log [H^+]$[/tex], where [tex]$H^+$[/tex] is the concentration of hydrogen ions. Which equation models the concentration of hydrogen ions ([tex]$H^+$[/tex]) of a solution whose pH is 7.2? A. [tex]$[H^+] = \log 7.2$[/tex] B. [tex]$[H^+] = -\log 7.2$[/tex] C. [tex]$[H^+] = 10^{-7.2}$[/tex] D. [tex]$[H^+] = 10^{7.2}$[/tex]

[Terjawab] Which of the following is an incorrect representation for a neutral atom? (a) ${ }_3^6 Li $ (b) ${ }_6^{13} C$ (c) ${ }_{30}^{63} Cu$ (d) ${ }_{15}^{30} P$ (e) ${ }_{47}^{108} Ag$