Answer:
The mass number (represented by the letter A) is defined as the total number of protons and neutrons in an atom. Consider the element helium. Its atomic number is 2, so it has two protons in its nucleus.
The atomic mass of a single atom is simply its total mass and is typically expressed in atomic mass units or amu. By definition, an atom of carbon with six neutrons, carbon-12, has an atomic mass of 12 amu.
<span>The larger the GDP the better the overall economy of the country. It means more produced equals more for domestic consumption and hopefully an excess for export. It is essentially the production of wealth that will increase the standard of living for every citizen. Remember, GDP is the measure of the value of the gross domestic production of goods and services.</span>
I don't know how 5°C cooled to 85°C but the answer would be 12.878L
Answer:
68.3%
Explanation:
First, let us look at the equation of reaction involving silver and magnesium chloride:
2Ag + MgCl2 ----> 2AgCl + Mg
1 mole of MgCl2 is required to precipitate 2 moles of Ag completely from the solution. That is a ratio of 1 to 2.
Now, mole of MgCl2 used to precipitate all the Ag
= molarity x volume
= 2.19 M x 2.89/1000
= 0.0063291 mole
Since 1 mole of MgCl2 would always require 2 moles of Ag, 0.0063291 mole will therefore require:
0.0063291 x 2 = 0.0126 mole of Ag
This means that 0.0126 mole of Ag is present in stephanie.
Mass of silver in stephanie = mole x molar mass
= 0.0126 x 107.8682
= 1.365 g
Thus, 1.365 g of silver is present in 2.00 g sample of stephanie.
Mass percent of silver in stephanie = 1.365/2.00 x 100
= 68.25% = 68.3% to the correct number of significant figure.
The enthalpy of formation of CF
is -678.82 kJ/mol.
<h3>What is enthalpy ?</h3>
A thermodynamic system's enthalpy H is calculated by multiplying its internal energy by the product of its pressure and volume. In the equation H = U + pV, U stands for internal energy, p for pressure, and V for system volume; pV is also frequently referred to as the pressure energy P.
The amount of heat in a system under constant pressure is measured as enthalpy (H). Chemists frequently gauge how the enthalpy of chemical systems changes when reactants transform into products. The enthalpy change, which is the same thing as the heat that is absorbed or released by a process at constant pressure, is denoted by the letter H.
To learn more about enthalpy from the given link:
brainly.com/question/3393755
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