Answer:
THE HEAT NEEDED TO CHANGE 3KG OF WATER FROM 10 C TO 80 C IS 877.8kJ OR 877,800 J.
Explanation:
Mass = 3.0 kg = 3 * 1000 = 3000 g
Initial temperature = 10 C
Final temperature = 80 C
Change in temperature = 80 - 10 = 70 C
Specific heat of water = 4.18 J/g C
Heat needed = unknown
Heat is the amount of energy in joules needed to change a gram of water by 1 C.
Heat = mass * specific heat * change in temperature
Heat = 3000 g * 4.18 J/g C * 70 C
Heat = 877 800 Joules
Heat = 877.8 kJ.
The heat needed to change 3 kg mass of water from 10 C to 80 C is 877,800 J or 877.8 kJ.
Answer:
16.499 × 10∧ 21 atoms
Explanation:
Given data:
mass of P2O5= 0.560 g
number of atoms= ?
first of all we will calculate the molar mass of P2O5:
P = 2×31 g/mol = 62 g/mol
O = 5× 16 = 80 g/mol
molar mass of P2O5 = 142 g/mol
Noe we will find the moles of 0.560 g P2O5:
moles = mass / molar mass
moles = 0.560 g/ 142 g/mol
moles = 0.0039 mol
now we will find the atoms present in 0.0039 moles:
0.0039 × 6.02 × 10∧ 23 molecules
2.357 × 10∧ 21 molecules
P2O5 consist of 7 atoms:
2.357 × 10∧ 21 × 7 = 16.499 × 10∧ 21 atoms
There are 70.90g of Cl2 in 1 mol (because 35.45g Cl in one mol). So 77.1g/70.9g≈1.0874 mol.
Answer:
Arsenic
Explanation:
This is because it has atomic number 33
