Answer:
47.9 g of ethanol
Explanation:
Combustion is a chemical reaction in which a substance reacts with oxygen to produce heat and light. Combustion reactions have been very useful as a source of energy. Ethanol is now burnt for energy purposes as a fuel. Ethanol has even been proposed as a possible alternative to fossil fuels.
Since 1 mole of ethanol when combusted releases 1367 kJ/mol of energy
x moles of ethanol releases 1418 kJ/mol.
x= 1 × 1418 kJ/mol/ 1367 kJ/mol
x= 1.04 moles of ethanol.
Mass of ethanol = number of moles × molar mass
Molar mass of ethanol = 46.07 g/mol
Mass of ethanol = 1.04 moles × 46.07 g/mol
Mass of ethanol= 47.9 g of ethanol
Answer:
350 g dye
0.705 mol
2.9 × 10⁴ L
Explanation:
The lethal dose 50 (LD50) for the dye is 5000 mg dye/ 1 kg body weight. The amount of dye that would be needed to reach the LD50 of a 70 kg person is:
70 kg body weight × (5000 mg dye/ 1 kg body weight) = 3.5 × 10⁵ mg dye = 350 g dye
The molar mass of the dye is 496.42 g/mol. The moles represented by 350 g are:
350 g × (1 mol / 496.42 g) = 0.705 mol
The concentration of Red #40 dye in a sports drink is around 12 mg/L. The volume of drink required to achieve this mass of the dye is:
3.5 × 10⁵ mg × (1 L / 12 mg) = 2.9 × 10⁴ L
B. I’m sorry if I’m wrong ! Wasn’t sure about this question .
Answer:
Explanation:
Hola!
En este caso, consideramos que la disociación de ácido acético ocurre:
Así, mediante la solución del equilibrio ácido, podemos calcular la concentración de iones hidronio que posteriormente sirven para calcular el pH de la solución, por tal razón, debemos calcular el equilibrio dada la constante de equilibrio y por medio de la ley de acción de masas en términos del cambio 
como cualquier problema de equilibrio:
![Ke=\frac{CH_3COO^-][H^+]}{[CH_3COOH]}\\\\1.76x10^{-5}=\frac{x*x}{1x10^{-14}M-x}](https://tex.z-dn.net/?f=Ke%3D%5Cfrac%7BCH_3COO%5E-%5D%5BH%5E%2B%5D%7D%7B%5BCH_3COOH%5D%7D%5C%5C%5C%5C1.76x10%5E%7B-5%7D%3D%5Cfrac%7Bx%2Ax%7D%7B1x10%5E%7B-14%7DM-x%7D)
Resolviendo para , tenemos 
Así, la concentración de hidrógeno es igual a x, por lo que el pH:
![pH=-log([H^+])=-log(0.999x10^{-14})\\\\pH=14](https://tex.z-dn.net/?f=pH%3D-log%28%5BH%5E%2B%5D%29%3D-log%280.999x10%5E%7B-14%7D%29%5C%5C%5C%5CpH%3D14)
Dicho valor tiene sentido desde que la concentración de hidrógeno es casi despreciable, por lo que se puede asumir que tiende a ser básica.
Saludos!
