Answer:
700 calories
Explanation:
Using the formula below:
Q = m × c × ∆T
Where;
Q = amount of heat required (calories)
m = mass of substance (g)
c = specific heat of substance (cal/g°C)
∆T = change in temperature (°C)
According to this question, the following information was provided;
Q = ?
m = 20g
c = 1.0 cal/g °C
∆T = 40°C - 5°C = 35°C
Using the formula; Q = m × c × ∆T
Q = 20 × 1 × 35
Q = 700 calories
Hence, 700 cal of heat energy is needed to raise 20 g of H2O from 5°C to 40°C.
<u>Answer:</u> The temperature of the system is 273 K
<u>Explanation:</u>
To calculate the number of moles, we use the equation:
Given mass of carbon dioxide = 1 lb = 453.6 g (Conversion factor: 1 lb = 453.6 g)
Molar mass of carbon dioxide = 44 g/mol
Putting values in above equation, we get:
To calculate the temperature of gas, we use the equation given by ideal gas equation:
PV = nRT
where,
P = Pressure of carbon dioxide = 200 psia = 13.6 atm (Conversion factor: 1 psia = 0.068 atm)
V = Volume of carbon dioxide = 
(Conversion factor: 
)
n = number of moles of carbon dioxide = 10.31 mol
R = Gas constant = 
T = temperature of the system = ?
Putting values in above equation, we get:
Hence, the temperature of the system is 273 K
There are 0.566 moles of carbonate in sodium carbonate.
<h3>CALCULATE MOLES:</h3>
- The number of moles of carbonate (CO3) in sodium carbonate (Na2CO3) can be calculated by dividing the mass of carbonate in the compound by the molar mass of the compound.
- no. of moles of CO3 = mass of CO3 ÷ molar mass of Na2CO3
- Molar mass of Na2CO3 = 23(2) + 12 + 16(3)
- = 46 + 12 + 48 = 106g/mol
- mass of CO3 = 12 + 48 = 60g
- no. of moles of CO3 = 60/106
- no. of moles of CO3 = 0.566mol
- Therefore, there are 0.566 moles of carbonate in sodium carbonate.
Learn more about number of moles at: brainly.com/question/1542846
N -3
Ba +2
Sr +2
F -1
I -1
Ca +2
Mg +2
S -2
S -2
Al +3
//
Ba3N2
SrF2
CaI2
MgS
Al2S3
//
I don't really understand 2.
