Answer:
No, ΔE does not always equal zero because it refers to the systems internal energy, which is affected by heat and work
Explanation:
According to the first law of thermodynamics, energy is neither created nor destroyed. This implies that the total energy of a system is always a constant.
So, according to the first law of thermodynamics we have that ΔE = q + w. This means that the value of ΔE depends on q (heat) and w(work). Hence ΔE is not always zero since it depends on the respective values of q and w.
<span>9.40x10^19 molecules.
The balanced equation for ammonia is:
N2 + 3H2 ==> 2NH3
So for every 3 moles of hydrogen gas, 2 moles of ammonia is produced. So let's calculate the molar mass of hydrogen and ammonia, starting with the respective atomic weights:
Atomic weight nitrogen = 14.0067
Atomic weight hydrogen = 1.00794
Molar mass H2 = 2 * 1.00794 = 2.01588 g/mol
Molar mass NH3 = 14.0067 + 3 * 1.00794 = 17.03052 g/mol
Moles H2 = 4.72 x 10^-4 g / 2.01588 g/mol = 2.34140921086573x10^-4 mol
Moles NH3 = 2.34140921086573x10^-4 mol * (2/3) = 1.56094x10^-4 mol
Now to convert from moles to molecules, just multiply by Avogadro's number:
1.56094x10^-4 * 6.0221409x10^23 = 9.400197448261x10^19
Rounding to 3 significant figures gives 9.40x10^19 molecules.</span>
Answer:
using a more concentrated potassium hydroxide
Explanation:
<em>The option that would likely increase the rate of reaction would be to use a more concentrated potassium hydroxide.</em>
<u>The concentration of reactants is one of the factors that affect the rate of reaction. The more the concentration of the reactants, the faster the rate of reaction. </u>
Granted that there are enough of the other reactants, increasing the concentration of one of the reactants will lead to an increased rate of reaction.
Hence, using a more concentrated potassium hydroxide which happens to be one of the reactants would likely increase the rate of reaction.
Answer:
13.8072 kj
Explanation:
Given data:
Mass of water = 100.0 g
Initial temperature = 4.0 °C
Final temperature = 37.0°C
Specific heat capacity = 4.184 j/g.°C
Heat absorbed = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 37.0°C - 4.0 °C
ΔT = 33.0°C
Q = 100.0 g ×4.184 j/g.°C × 33.0°C
Q = 13807.2 j
Joule to KJ:
13807.2 j × 1kj /1000 j
13.8072 kj
<h3>The molecular formula of this protein : C₁₈H₄₂O₁₂N₆</h3><h3>Further explanation </h3>
The empirical formula is the smallest comparison of atoms of compound forming elements.
A molecular formula is a formula that shows the number of atomic elements that make up a compound.
(empirical formula) n = molecular formula
The principle of determining empirical formula and molecular formula
- Determine the mass ratio of the constituent elements of the compound.
- Determine the mole ratio by dividing the elemental mass with the relative atomic mass obtained by the empirical formula
- Determine molecular formulas by looking for values of n
Find mol ratio for every component :
N (r=14 g/mol) :
Mass of Nitrogen :
40.4-(17.16+3.17+13.71)=6.36 g
C : H : O : N = 1.43 : 3.17 : 0.857 : 0.454 = 3.15 : 7 : 1.89 : 1=3:7:2:1
Empirical formula : C₃H₇O₂N
Molecular mass of protein :
(C₃H₇O₂N)n=565.75
(12.3+1.7+2.16+14)n=565.75
(89)n=565.75
n=6.4≈6
so the molecular formula : C₁₈H₄₂O₁₂N₆
