Explanation:
1 Cal of energy is equivalent to 4.184 Joules.
A.
770Cal of energy = 3221.680 joules
Therefore, 780kCal of energy = 3221680 Joules.
B.
3200000 Joules (in 2 s.f).
C.
I000 joules = 1 kJoule
3221680 joules = 3221.689 kJoules.
D.
3200 kJ (in 2 s.f).
Answer:
The pH of the solution is 1.34, being an acidic pH.
Explanation:
pH is a measure of acidity or alkalinity that indicates the amount of hydrogen ions present in a solution or substance.
The acronym pH stands for hydrogen potential.
The pH scale ranges from 0 to 14. Values less than 7 indicate the acidity range and those greater than 7 indicate alkalinity or basicity. Value 7 is considered neutral. Mathematically, pH is the negative logarithm of the molar concentration of hydrogen or proton ions (H⁺) or hydronium ions (H₃O⁺).
pH= - log [H⁺] = - log [H₃O⁺]
In this case, [H⁺]= 4.6*10⁻² M. Replacing:
pH= - log 4.6*10⁻²
Solving:
pH= 1.34
<u><em>
The pH of the solution is 1.34, being an acidic pH.</em></u>
<u><em></em></u>
Explanation:
In the attachment fig ABCD is a parallelogram with AC as diagonal.
we know that,
In a parallelogram opposite sides are equal and parallel
In a parallelogram sum of adjacent angles is 180°
that is
∠A+∠D= ∠B+∠C= 180°
Also, in a parallelogram opposite angles are equal.
So in ΔADC and ΔABC
1) AD=BC
2) DC= AB
And
3) ∠ADC= ∠ABC
therefore, ΔADC and ΔABC are congruent to each other and Emily was right.
Higher <span>C. higher than when the source is stationary</span>
