Answer is: formula of the complex is [Cr(NH₃)₂(SCN)₄<span>]</span>⁻<span>.
This complex has negative charge (-1) because chromium (central atom or metal) has oxidation number +3, first ligand ammonia has neutral charge and second ligand thiocyanate has negative oxidation number -1:
+3 + 2</span>·0 + 4·(-1) = -1.
Based on the balanced chemical reaction presented above, every mole of magnesium (Mg) yields one mole of diatomic hydrogen (H2). When converted to masses, every 24.3 grams of magnesium yields 2 grams of hydrogen.
From the given, there are 20 grams of magnesium available for the reaction. With this amount, the expected yield of hydrogen is 1.646 grams. To calculate the percent yield, divide the actual yield to the hypothetical yield.
*The case is impossible because the actual yield is greater than the theoretical yield.
If we assume that there had been a typographical error and that the actual yield is 0.7 grams instead of 1.7 grams, the percent yield becomes 42.5%. Thus, the answer is letter E.
The Moon<span> moves </span>around<span> the </span>Earth in<span> an </span>approximately<span> circular </span>orbit<span>, going once </span>around<span> </span>in approximately<span> 27.3 </span><span>days. </span>The moon orbits quite fast: it moves about 0.5 degrees<span> per hour in the sky. So, its average movement in a day is around 13 degrees. 5 days x 13 degrees is approximately 65 degrees. </span>
Answer:
2Ca + O₂ → 2CaO
Explanation:
Cuando el Calcio (Ca) reacciona con oxígeno (O₂) se produce cal (CaO). La cal es un sólido inodoro de color blanco a grisáceo. La cal es un óxido que se encuentra presente en el cemento y su cuantificación permite determinar la calidad y el tipo de cemento a utilizar.
La reacción que describe el proceso anterior es:
Ca + O₂ → CaO
Para balancear los oxígenos, se deben poner 2 CaO como producto:
Ca + O₂ → 2CaO
Para balancear los calcios, se pone como coeficiente del Ca un 2:
<h3>2Ca + O₂ → 2CaO</h3><h3 />
Esta última es la reacción que describe el proceso anterior
