Acceso
Prima
Hogar Banco de preguntas Química Archive 2024 December 31

Chemistry Questions from Dec 31,2024

Browse the Chemistry Q&A Archive for Dec 31,2024, featuring a collection of homework questions and answers from this day. Find detailed solutions to enhance your understanding.

error msg
\begin{tabular}{l} EMESTRADA \\ EXAMENESDE \\ SELECTIVIDAD \\ En la reacción del oxigeno molecular gaseoso con el cobre para formar óxido de cobre(II) se \\ desprenden \( 2,30 \mathrm{~kJ} \) por cada gramo de cobre que reacciona, a 298 K y 760 mmHg . Calcule: \\ a) La entalpía de formación del óxido de cobre(II). \\ b) El calor desprendido a presión constante cuando reaccionan 100 L de oxígeno, medidos a 1,5 \\ atm y \( 27^{\circ} \mathrm{C} \). \\ Datos: \( \mathrm{R}=0^{\prime} 082 \mathrm{~atm} \cdot \mathrm{~L} \cdot \mathrm{~mol}^{-1} \cdot \mathrm{~K}^{-1} \). Masa atómica Cu=63,5 \\ QUÍMICA. 2013 . JUNIO. EJERCICIO 6. OPCIÓN A \\ \hline\end{tabular} \( \leftarrow \rightarrow G \) cacademyzonecom///exam/103 [3-630] Compound (A): is produced from the reduction of iron Ill oxide in the midrex furnace, then treating the solid prode with diluted sulphuric acid. Compound (B): is a stable chloride salt of the most abundant metal of the Earth's crust So, to differentiate between compound (A) and compound (B) we use ............. a) sodium hydroxide b) dil. hydrochloric acid c) conc. sulphuric acid d) more than one is correct. 7) Which box from Model 2 represents an element? * 1 point \( A \) B C D E 8) Which box from Model 2 represents a mixture of 2 elements? * 1 point A B C D E \begin{tabular}{l} Physical vs. Chemical \\ 5) Click all of the boxes that are physical properties of iron. * \\ Iron corrodes in moist air. \\ Density of iron is \( 7.84 \mathrm{~g} / \mathrm{mL} \). \\ Iron is soft when pure. \\ Iron melts at 1538C \\ 6) Is grilling meat during a cookout an example of a physical change or \\ chemical change? Explain your thinking. \\ Your answer 2 points \\ \hline Back \\ Next \end{tabular} \begin{tabular}{l} art 3: Pure Air \( \left(\mathrm{N}_{2}+\mathrm{O}_{2}+\mathrm{CO}_{2}\right) \) is a homogeneous mixture. Is polluted air also a homogeneous mixture or is it \\ heterogeneous mixture? Explain your thinking in CER format. Use complete sentences in each part of the \\ CER format. \\ \begin{tabular}{l|l|l|} Claim: What type of \\ mixture is polluted city air? \end{tabular} \\ \hline \( \begin{array}{l}\text { Evidence: What is the } \\ \text { chemical formula for pure } \\ \text { air? List speciic evidence } \\ \text { that you see of polluted city } \\ \text { air from the slides. }\end{array} \) \\ \hline \begin{tabular}{|l|l|}\hline Reasoning: Connect your & \\ evidence back to your \\ claim. How does your \\ evidence support your \\ claim? \end{tabular} \\ \hline\end{tabular} [3-441] Hydrocyanic acid is one of the weak acids which is incompletely ionized, and its ionization is according to the following equation: \[ \mathrm{HCN}_{(\mathrm{aq})}+\mathrm{H}_{2} \mathrm{O}_{(0)} \rightleftharpoons \mathrm{H}_{3} \mathrm{O}^{+}(\mathrm{aq})+\mathrm{CN}^{-}(\mathrm{aq}) \] On adding drops of \( \mathrm{H}_{2} \mathrm{SO}_{4} \) solution: the concentration of \( \mathrm{CN}^{-} \)will ...... and on adding drops of KOH solution: the concentration of \( \mathrm{CN}^{-} \)will ...... a) decreases, increases b) increases, increases c) increases, decreases d) decreases, decreases [ \( 3-390 \) ] In the following hypothetical reaction: \( \mathrm{A}+\mathrm{B} \rightleftharpoons \mathrm{AB} \) The energy of the reactants \( =40 \mathrm{KJ} \), the energy of the product \( =60 \mathrm{KJ} \), and the activation energy for the backward reaction is 100 KJ , so the activation energy of the forward reaction =,.......... a) 120 KJ b) 20 KJ c) 40 KJ d) 10 KJ Directions: For cach of the following compounds, fill in dots to represent electrons. Then, draw arrows to show the transfer of electron(s). Then, write the chemical formula, electron donor (which atom gives up \( 1-2 \) electrons?), and electron acceptor. 1) Why do atoms form ionic bonds (hint: it has to do with electron rings)? 2) Sodimes 5:4 Hur många mol atomer av varje grundämne 2 finns det i \( 0,75 \mathrm{~mol} \) av följande föreningar: a) \( \mathrm{Fe}_{3} \mathrm{O}_{4} \), b) \( \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3} \), c) \( \mathrm{Ca}\left(\mathrm{C}_{2} \mathrm{H}_{3} \mathrm{O}_{2}\right)_{2} \), d) \( \mathrm{Ba}(\mathrm{OH})_{2} \cdot 8 \mathrm{H}_{2} \mathrm{O} \). La soluzione \( S_{1} \) è ipertonica rispetto alla soluzione \( S_{2} \), pertanto: A. \( S_{2} \) esercita una pressione osmotica maggiore rispetto a \( S_{1} \) B. \( S_{1} \) congela a temperatura più elevata rispetto a \( S_{2} \) C. La temperatura di ebollizione di \( S_{1} \) è minore della temperatura di ebollizione di \( S_{2} \) D. \( S_{2} \) è maggiormente concentrata nelle stesse condizioni di temperatura la tensione di vapore di \( S_{2} \) è maggiore della tensione di vapore di \( S_{1} \)
Anterior 1 2 Próximo
1 2
Anterior Próximo
Estudiar puede ser una verdadera lucha
¿Por qué no estudiarlo en UpStudy?
Seleccione su plan a continuación
Prima

Puedes disfrutar

Empieza ahora
  • Explicaciones paso a paso
  • Tutores expertos en vivo 24/7
  • Número ilimitado de preguntas
  • Sin interrupciones
  • Acceso completo a Respuesta y Solución
  • Acceso completo al chat de PDF, al chat de UpStudy y al chat de navegación
Básico

Totalmente gratis pero limitado

  • Solución limitada
Bienvenido a ¡Estudia ahora!
Inicie sesión para continuar con el recorrido de Thoth AI Chat
Continuar con correo electrónico
O continuar con
Al hacer clic en "Iniciar sesión", acepta nuestros términos y condiciones. Términos de Uso & Política de privacidad