physical change
particles retain there composition and identity
there is no change in there chemical properties of the substance
the chemical changes should be the other two.
If it is wrong I'm truly sorry.
Answer:
maybe speak in english than we can understand and help you sorryy
Answer:
Explanation:
Mg + 2HCl = Mg Cl₂ + H₂
.594 g = .594 / 24.3
= .02444 mole
Heat evolved = msΔ T , m is mass of water ( solvant ) , s is specific heat of water , Δ T is rise in temperature
= 100 x 4.2 x ( 41.83 - 25 )
= 7068.6 J
.02444 mole of Mg evolves 7068.6 J of heat
1 mole of Mg evolves 7068.6 /.02444 J
= 289222.6 J
= 289 kJ .
Molar heat enthalpy = 289 kJ .
V1/T1 = V2/T2
Substitute the value use ratio and proportion. Use calculator.
V1 = (V2 x T1) / T2
1 is initial, 2 is final
Answer:
8.73
Explanation:
when you are adding or subtracting numbers, the sigfig (significant figure) is based on how many numbers after the decimal. with this info, we can see that 15.67 has 2 sigfigs and 6.943 has 3 sigfigs. when you subtract normally, you would get 8.727, which has 3 sigfigs, so you would round the last 7 up to get 8.73 with 2 sigfigs!
also it is to 2 sigfigs because we know that we go by the least number of sigfigs. hope this helped!