First, calculate for the amount of heat used up for increasing the temperature of ice.
H = mcpdT
H = (18 g)*(2.09 J/g-K)(50 K) = 1881 J
Then, solve for the heat needed to convert the phase of water.
H = (1 mol)(6.01 kJ/mol) = 6.01 kJ = 6010 J
Then, solve for the heat needed to increase again the temperature of water.
H = (18 g)(4.18 J/gK)(70 k)
H = 5266.8 J
The total value is equal to 13157.8 J
Answer: 13157.8 J
When lithium reacts to chlorine it goes from having no charge to +1 charge, while chlorine goes from neutral to having -1 charge.
Answer:
5.45*10⁻⁴ moles of silane gas (SiH₄) are present in 8.68 mL measured at 18°C and 1.50 atm.
Explanation:
An ideal gas is a theoretical gas that is considered to be composed of point particles that move randomly and do not interact with each other. Gases in general are ideal when they are at high temperatures and low pressures.
An ideal gas is characterized by three state variables: absolute pressure (P), volume (V), and absolute temperature (T). The relationship between them constitutes the ideal gas law, an equation that relates the three variables if the amount of substance, number of moles n, remains constant and where R is the molar constant of the gases:
P * V = n * R * T
In this case:
- P= 1.5 atm
- V= 8.68 mL= 0.00868 L (being 1000 mL= 1 L)
- n= ?
- R= 0.082

- T= 18 C= 291 K (being 0 C= 273 K)
Replacing:
1.5 atm* 0.00868 L= n* 0.082
*291 K
Solving:

n= 5.45*10⁻⁴ moles
<u><em>5.45*10⁻⁴ moles of silane gas (SiH₄) are present in 8.68 mL measured at 18°C and 1.50 atm.</em></u>
I would say 6.022<span>⋅1023 atom</span>
The answer is B. Unit cell.
Hoped I Helped!