Answer:
magnesium
Explanation:
magnesium is in Group 2, in the periodic table. this means that it has 2 valence electrons. the less valence electrons an element or atom has, the more reactive. Selenium has 6 valence electrons. as a result, Mg is more reactive
Answer: 44g
Explanation: The formular for finding Moles is ;
Moles = Mass / Molar Mass or Formular Mass.
Base on this question; Moles = 10, Mass = 440g, and Formular Mass = ?
Making 'Formular Mass', subject of the formular; we thus have;
Formular mass = Mass / Moles = 440/ 10 = 44g
Pressure given by:
Pressure=(force)/(area)
Force=Mass*gravitational pull
Mass=34Kg
gravity=9.80
so,
force=34*9.8=333.2
thus;
pressure=333.2/25=13.328=13.3 N/cm^2
Hope this helped :)
Answer:
2.25g of NaF are needed to prepare the buffer of pH = 3.2
Explanation:
The mixture of a weak acid (HF) with its conjugate base (NaF), produce a buffer. To find the pH of a buffer we must use H-H equation:
pH = pKa + log [A-] / [HA]
<em>Where pH is the pH of the buffer that you want = 3.2, pKa is the pKa of HF = 3.17, and [] could be taken as the moles of A-, the conjugate base (NaF) and the weak acid, HA, (HF). </em>
The moles of HF are:
500mL = 0.500L * (0.100mol/L) = 0.0500 moles HF
Replacing:
3.2 = 3.17 + log [A-] / [0.0500moles]
0.03 = log [A-] / [0.0500moles]
1.017152 = [A-] / [0.0500moles]
[A-] = 0.0500mol * 1.017152
[A-] = 0.0536 moles NaF
The mass could be obtained using the molar mass of NaF (41.99g/mol):
0.0536 moles NaF * (41.99g/mol) =
<h3>2.25g of NaF are needed to prepare the buffer of pH = 3.2</h3>
Answer:
ionic compounds contain a metal and a non metal
covalent compounds contain only non metals
Explanation:
Each type of compound is named according to different rules.