Answer: final temperatures will be
a) water 21 C
b) concrete 20.005 C
c) steel 20.008 C
d) mercury 53 C
Explanation:
Change in temp dT = dH / (mass x specific heat)
Specific heat of these materials can be found from many sources:
water = 1 kcal / kg C
concrete = 210 kcal / kg C
steel = 114 kcal / kg C
mercury = 0.03 kcal /kg C
So dT (water) from 1 kcal heat into 1 kg water = 1 kcal / (1 kg x 1 kcal/kg C) = 1 C therefore the final temperature is 20 + 1 = 21 C
But dT (steel) = 1 kcal / (1kg x 114 kcal/kg C) = 0.008 C so the final temperature is 20 + 0.008 = 20.008 C
The results for concrete and mercury are calculated in the same way
Answer:
Mass of sodium metal is 130.87 gram
Explanation:
The complete reaction is
2 NaN3 --> 2 Na + 3 N2
We know that PV = nRT
n = 
On substituting the given values, we get
moles of N2
Sodium azide's molar mass
3.02 *(2/3) = 2.013 moles
Mass = 2.03 * 65.01 = 130.87 gram
Answer:
BaBr2 (aq) + H2SO4 (aq) → BaSO4 (s) + 2 HBr (aq)
Explanation:
This is a precipitation reaction: BaSO4 is the formed precipitate.
Answer:
Tetrahedral electron geometry and trigonal pyramidal molecular geometry.
Explanation:
The Lewis structure is shown in Figure 1.
The central N atom has three bonding pairs and one lone pair, for <em>four electron groups</em>.
VSEPR theory predicts a tetrahedral electron geometry with bond angles of 109.5°.
We do not count the lone pair in determining the molecular shape.
The molecular geometry is trigonal pyramidal (see Figure 2).