Answer: conversion of ice to steam
Explanation: Endothermic process is one in which energy is absorbed by the system.
Conversion of ice to steam is change of solid phase to gaseous phase, thus energy is required to break the strong inter molecular forces of attraction in solids to convert it into gaseous phase.
Conversion of steam to ice, conversion of steam to water and conversion of water to ice releases energy and are examples of exothermic processes.
The equation is as follows;
2CH3OH(g) = 2CH4(g) + O2(g), ΔH= +252.8 kJ
From the equation; for the reaction to produce 2 moles of methane (32g) an energy of 252.8 kJ is released.
Therefore; for an energy of 82.3 kJ the number of moles that will be produced will be; = (2×82.3)/252.3
= 0.6524 moles
which is equivalent to 0.6524 × 16 = 10.438 g
There, the mass of CH4 produced will be 10.438 g
The answer is A but i'm not sure .
Empirical Formulae for;
Compound 1- K5 Mn5 O16
Compound 2- Na2 Cr2 O7
Compound 3- C3 H4 O4
Compound 4- C3 H3 O1
Explanation:
Step 1; as all the element percentages are given in percent assume the total mass of the compound is 100g and take each percentage as grams i.e., 27.5% of K as 27.5 g of K and so on.
Step 2; convert the mass of each element into their mole values by dividing available mass by molar masses.
Molar masses of required elements are as follows; K=39, Mn=55, O=16 C=12, H=1, Na=23, Cr=52.
Step 3; Divide all the values by the smallest mole value. I.e. for compound 1 after dividing the masses by molar masses we get 0.705, 0.681, and 2.187 for elements K, Mn, O respectively. Divide all three values with the least value which is 0.681 and write these values down.
Step 4; Convert all the numbers available into whole numbers by multiplying with suitable values. i.e. 3 if values are 0.33, 2 if values are 0.5 etc.
Step 5; Assign these values to corresponding elements and you will get the above empirical formula.
Explanation:
Protons are the positively charged particles found in an atom.
- A proton is found within the nucleus of an atom.
- Together with the neutron, they make up the nuclear region of an atom.
Protons and neutrons constitutes the bulk mass of the atom.
The mass of a proton is 1.67 x 10⁻²⁷kg
The proton have the same mass as neutrons.
Compared to electrons, it is 1840 times the mass of an electron.
