Answer:
m = 4450 g
Explanation:
Given data:
Amount of heat added = 4.45 Kcal ( 4.45 kcal ×1000 cal/ 1kcal = 4450 cal)
Initial temperature = 23.0°C
Final temperature = 57.8°C
Specific heat capacity of water = 1 cal/g.°C
Mass of water in gram = ?
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 = 57.8°C - 23.0°C
ΔT = 34.8°C
4450 cal = m × 1 cal/g.°C × 34.8°C
m = 4450 cal / 1 cal/g
m = 4450 g
Answer:
im sorry but this question doesnt make sense
Explanation:
Answer:
mL of NaOH required =29.9mL
Explanation:
Let us calculate the moles of vitamin C in the tablet:
The molar mass of Vitamin C is 176.14 g/mole
Thus we need same number of moles of NaOH to reach the equivalence point.
For NaOH solution:
Answer:- C. Hafnium.
Solution:- Mass of the sample is 46.0 g and it's volume is 
.
From mass and volume, we can calculate it's density using the formula:
On the basis of the density, this substance could either be mercury or hafnium. Since the substance is a solid at room temperature where as mercury is liquid. So, it can't be mercury.
The right choice is C) Hafnium.
Answer: the second option: <span>Iron is being oxidized
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Explanation:
1) Oxidation is the increase of the oxidation state (number) due to the loss of electrons.
2) In the given reaction, you can see that in the left side the atom is Fe.
When an element (atom) is not combined (or combined with it self) its oxidation state is 0.
3) In the right side of the given equation you that iron is now in form of cation with charge 2+: Fe²⁺.
That means that the new oxidation state of the element is 2+.
4) This change in the oxidation state, of course, is accompanied by the loss of the two electrons: 2e⁻.
5) Conclusion: the iron has oxidized by losing two electrons and increasing its oxidation state from 0 to 2+.
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