Answer:
Explanation:
The kPa-kilopascal is the unit of pressure. It was named after Blaise Pascal, a mathematician and physicist.
The kPa is 1000Pa. Kilo stands for 1000. Now what is a pascal?
A pascal is the amount of force(Newton) exerted per unit area.
1Pa = 1Nm⁻²
At the standard atmospheric level, the pressure is 101.325 x 10³ Nm⁻² i.e the atmosphere exerts a pressure of 101.325 x 10³N in an area of a body.
This unit is used to calculate pressure. It can be converted to other units.
Answer:
2.9 grams.
Explanation:
- From the balanced reaction:
<em>Mg + 1/2O₂ → MgO,</em>
1.0 mole of Mg reacts with 0.5 mole of oxygen to produce 1.0 mole of MgO.
- We need to calculate the no. of moles of (1.8 g) of Mg and (6.0 g) of oxygen:
no. of moles of Mg = mass/molar mass = (1.8 g)/(24.3 g/mol) = 0.074 mol.
no. of moles of O₂ = mass/molar mass = (6.0 g)/(16.0 g/mol) = 0.375 mol.
<em>So. 0.074 mol of Mg reacts completely with (0.074/2 = 0.037 mol) of O₂ which be in excess.</em>
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<em><u>Using cross multiplication:</u></em>
1.0 mole of Mg produce → 1.0 mol of MgO.
∴ 0.074 mol of Mg produce → 0.074 mol of MgO.
<em>∴ The amount of MgO produced = no. of moles x molar mass </em>= (0.074 mol)(40.3 g/mol) = <em>2.98 g.</em>
Total number of atoms = 7
Total number of H atom = 5
% of H in ammonium hydroxide = 5/7 ×100 = 71.4 %