Answer:
5.90x10²² atoms of gold are present in the cube
Explanation:
First, we must find the volume of the cube in cm³. With density we can find the mass of the gold and the moles using its molar mass. As 1 mol = 6.022x10²³ atoms we can find the number of atoms:
<em>Volume in cm³:</em>
(10.0mm)³ = 1000mm³
<em>1mm³ = 0.001cm³</em>
1000mm³ * (0.001cm³ / 1mm³) = 1cm³
<em>Mass gold:</em>
1cm³ * (19.3g/cm³) = 19.3g Gold
<em>Moles Gold:</em>
19.3g * (1mol / 197.0g) = 0.0980 moles Gold
<em>Atoms gold:</em>
0.0980 moles Gold * (6.022x10²³ atoms / mol) =
<h3>5.90x10²² atoms of gold are present in the cube</h3>
Answer:
0.200 M
Explanation:
Begin by finding how many moles of KCl there are by using the molarity and given volume:
(Remember that molarity is mol/L, which is equal to mol/1000 mL.)
Next, divide the moles of KCl by the new volume (after dilution):
The new concentration is 0.200 M.