Answer:
2H2(g) + O2(g) --------> 2H2O(g). ∆H= -242KJmol-1
Explanation:
A thermochemical equation is a balanced chemical reaction equation that includes the physical states of all reactants and products and the energy change.
As shown above, hydrogen reacted with oxygen in the gas phase to form water, an energy of 242KJ was evolved and we are required to put this in a thermochemical equation using the least coefficients.
Hydrogen reacts with oxygen to form water in the gas phase in a least ratio of 2:1 as shown in the answer.
The term 'energy evolved' in the question means that the reaction is exothermic and energy is evolved. Hence ∆H is negative as shown.
Questions:
The questions or computes to do are:
<span>a- a massa, em
kg, de cada placa de alumínio;
b- a quantidade mínima de viagens
necessárias para que apenas um veículo de transporte entregue o material
solicitado ao cliente.
Dado: densidade do alumínio = 2,7 g/cm3
Answer:
a) mass in kg of every aluminum plate
Dimensions of every aluminum plate: </span>
<span>2 M X 50 Cm X 2cm
Volume: 200 cm * 50 cm * 2 cm = 20,000 cm^3
Mass:
density = mass / volume => mass = density * volume = 2.7 g/cm^3 * 20,000 cm^3 = 54,000 g = 54 kg.
Answer: the mass of everyplate of aluminum is 54 kg.
b) number of travels required for one truck deliver all the material:
number of travels = amount requested / amount that a truck can deliver in one travel.
amount requested: 100 plates
mass of 100 plates = 100 plates * 54 kg / plate = 5,400 kg
limit of transport per travel: 3 tons = 3,000 kg
number of travels = 5,400 kg / 3,000 kg/travel = 1.8 travels => 2 travels.
Answer: at least 2 travels.
</span>
Answer:
17
Explanation:
the atomic mass is away protons + neutrons, electrons are neglatable.
<span>arsenic is the element often used in rat poison.</span>
Answer:
precipitation reactions
Explanation:
insoluble salts can be formed/produced by precipitation reactions
