Answer:
454.3 g.
Explanation:
1.0 mol of CaO liberates → – 64.8 kJ.
??? mol of CaO liberates → - 525 kJ.
∴ The no. of moles needed = (1.0 mol)(- 525 kJ)/(- 64.8 kJ) = 8.1 mol.
<em>∴ The no. of grams of CaO needed = no. of moles x molar mass</em> = (8.1 mol)(56.077 g/mol) = <em>454.3 g.</em>
GEORGEOCTOBER 18, 2012Floor Wax is Harmful to the Environment
Floor wax is applied on floor surfaces to make it scuff-resistant, water-resistant, slip resistant and glossy. It provides a thin, protective and hard surface layer when applied to flooring. Conventional floor wax has five main ingredients and each one of them has detrimental effects on the environment, not to mention the chemical waste created by the continuous upkeep required. The cumulative effects of these ingredients on the environmental render their harmful actions more potent and difficult to reverse.
Answer:
1.8g
Explanation:
Initial volume = 43.5ml
Final volume = 49.4ml
Mass = 10.88g
Density = ?
Volume = Final volume - initial volume
= 49.4 - 43.5
= 5.9ml
Density = Mass/volume
Density = 10.88/5.9
= 1.8g/ml
The number of moles of aluminium that are needed to react completely with 13.2 moles of FeO is 8.8 moles
calculation
2Al + 3FeO → 3aFe +Al2O3
by use of of mole ratio of Al: FeO from equation above = 2:3 the moles of Al is therefore
= 13.2 x 2/3=8.8 moles of Al
Answer:
Option D: More than 30 seconds
Explanation:
The enzyme CATALASE is found in almost all living organisms. CATALASE helps in the decomposition of one substance into another substance. CATALASE will breaks down hydrogen peroxide into water and oxygen.
When the potatoes were boiled it will surely produce no bubbles because the heat would have degrade the enzyme - catalase While the potatoes at room temperature potato produced the most bubbles because catalase works best at a room temperature.
If the potato solution was boiled for 10 minutes and cooled for 10 minutes before being tested, the average time for the disks to float to the surface of the hydrogen peroxide solution would be MORE THAN 30 SECONDS
