Answer:
Heat required to melt 26.0 g of ice at its melting point is 8.66 kJ.
Explanation:
Number of moles of water in 26 g of water: 26× 
moles
=1.44 moles
The enthalpy change for melting ice is called the entlaphy of fusion. Its value is 6.02 kj/mol.
we have relation as:
q = n × ΔH
where:
q = heat
n = moles
Δ
H = enthalpy
So calculating we get,
q= 1.44*6.02 kJ
q= 8.66 kJ
We require 8.66 kJ of energy to melt 26g of ice.
<h2>Answer : By weighing the costs and benefits of an environmental issue
</h2><h3>
Explanation :</h3>
The law makers usually conduct many studies before a law is imposed. They try to explore many other options available to the current environmental issue and then come to a conclusion to make a law.
They also weigh the cost aspect along with the benefit of the ongoing environmental issue. They try to come up with something which appears to be cost effective and result bearing.
Answer:
C₄H₂N₂
Explanation:
First we<u> calculate the moles of the gas</u>, using PV=nRT:
P = 2670 torr ⇒ 2670/760 = 3.51 atm
V = 300 mL ⇒ 300/1000 = 0.3 L
T = 228 °C ⇒ 228 + 273.16 = 501.16 K
- 3.51 atm * 0.3 L = n * 0.082atm·L·mol⁻¹·K⁻¹ * 501.16 K
Now we<u> calculate the molar mass of the compound</u>:
- 2.00 g / 0.0256 mol = 78 g/mol
Finally we use the percentages given to<em> </em><u>calculate the empirical formula</u>:
- C ⇒ 78 g/mol * 61.5/100 ÷ 12g/mol = 4
- H ⇒ 78 g/mol * 2.56/100 ÷ 1g/mol = 2
- N ⇒ 78 g/mol * 35.9/100 ÷ 14g/mol = 2
So the empirical formula is C₄H₂N₂
Atomic mass silicon = 28.085 u
1 mol Si ---------------- 28.085 g
? ------------------------ 245 g
245 x 1 / 28.085 => 8.72 mol
answer A
