A chemical reaction undergoes a chemical change so the question you should ask if a chemical reaction has occurred is "Did a chemical change happened?". Chemical change in a reaction happens when you see bubbles, when the reaction increases or decreases in temperature or a precipitate is formed.
Answer:
2.803013439419911 × 10⁻¹² J
Explanation:
Mass defect = mass of reactant - mass of product
(2.0140 + 3.01605) - (4.002603 + 1.008665)
5.03005 - 5.011268 = 0.018782 amu
mass in Kg = mass (amu) × 1.66053892173 × 10⁻²⁷ kg
mass in kg = 0.018782 × 1.66053892173 × 10⁻²⁷ = 3.1188242027932 × 10⁻²⁹kg
E = Δm c² where c is the speed of light = 2.9979 × 10⁸m/s
E = 3.1188242027932 × 10⁻²⁹kg × (2.9979 × 10⁸m/s)² = 2.803013439419911 × 10⁻¹² J
Answer:
[α] = -77.5° / 
Explanation:
Given;
Mass of optically pure substance in the solution = 10 g
Volume of water = 500 mL
Length of the polarimeter, l = 20 cm = 20 × 0.1 dm = 2 dm
measured rotation = - 3.10°
Now,
The specific rotation ( [α] ) is given as:
[α] = 
here,
α is the measured rotation = -3.10°
c is the concentration
or
c = 
or
c = 
or
c = 0.02 g/mL
on substituting the values, we get
[α] = 
or
[α] = -77.5° /
Answer:
C6H6
Explanation:
We can obtain the molecular formula from the empirical formula.
What we need do here is:
(CH)n = 78
The n shows the multiples of both element present in the actual compound. It can be seen that carbon and hydrogen have the same element ratio here. We then use the atomic masses of both elements to get the value of n. The atomic mass of carbon is 12 a.m.u while the atomic mass of hydrogen is 1 a.m.u
(1 + 12)n = 78
13n = 78
n = 78/13 = 6
The molecular formula is
(CH)n = (CH)6 = C6H6
Option C coz it should be ( CNH4)2. Hope i cleared your doubt
