Answer:
145 hours
Explanation:
Since one hour of riding a bicycle takes up 505 kcal of energy. It is also stated that one gram of body fat is equal to 7.70 kcal. Also, it is given that 1 pound of body fat is equal to 454 g.
Hence;
1 Ib= 454 g
21 Ib= 21 × 454/1 = 9534 g
But
1g of body fat = 7.70kcal
9534 g of body fat = 9534 × 7.70 kcal/1 = 73411.8 kcal
If 505 kcal is lost in 1 hour
73411.8 kcal is lost in 73411.8 kcal × 1hour/505k cal = 145 hours
<u>Answer:</u>
Specific heat of a substance is the value that describe how the added heat energy of substance has the impact on its temperature.
Unit is <em>
</em>
<em>C = Q/m. ∆T</em>
<em>C – Specific heat </em>
<em>Q- heat energy (J)</em>
<em>M – Mass (Kg)</em>
<em>∆T- change in temperature (K) </em>
<u>Explanation:</u>
<em>Given data:</em>
<em>M= 140 g = 0.14 Kg</em>
<em>Q – 1080 Joules.</em>
<em>∆T – 98.4 – 62.2 = 36.2</em>
Substituting the given data in Equation
<em>Specific heat of Aluminium = 
</em>
Answer:
27.0
Explanation:
Because Mass can neither be created nor be destroyed hence total mass of sample of iodine and tube remain equal as it is sealed.
Answer: 91.73g of NaCl
Explanation:
First, we solve for the number of moles of F2 using the ideal gas equation
V = 12L
P = 1.5 atm
T = 280K
R = 0.082atm.L/mol/K
n =?
PV = nRT
n = PV /RT
n = (1.5x12)/(0.082x280)
n = 0.784mol
Next, we convert this mole ( i.e 0.784mol) of F2 to mass
MM of F2 = 19x2 = 38g/mol
Mass conc of F2 = n x MM
= 0.784 x 38 = 29.792g
Equation for the reaction is given below
F2 + 2NaCl —> 2NaF + Cl2
Molar Mass of NaCl = 23 + 35.5 = 58.5g/mol
Mass conc. of NaCl from the equation = 2 x 58.5 = 117g
Next, we find the mass of NaCl that reacted with 29.792g of F2.
From the equation,
38g of F2 redacted with 117g of NaCl.
Therefore, 29.792g of F2 will react with Xg of NaCl i.e
Xg of NaCl = (29.792 x 117)/38
= 91.73g
Therefore, 91.73g of NaCl reacted with f2
