A slingshot that has been pulled back but has not been let go.

if you can’t already tell by the amount of questions i do not understand chemistry lol, giving brainliest

Vladimir [108]

Answer:

Ok, so the process here is to convert the mass of H2 (hydrogen gas) to moles by dividing the mass by the molar mass of H2. Once you have the moles then you have to multiply by the STP (standard temperature and pressure) molar volume which should be 22.4.

Molar mass of H2 = (1.01)x2 = 2.02g/mol

19.3/2.02 = 9.55 moles

Now just multiply the moles by the molar volume

9.55 moles x 22.4 = 213.92 Litres of H2 are in 19.3g of H2

6 0

2 years ago

What is the freezing point of an aqueous solution that has 25.00 g of calcium iodide dissolved in 1250 g of water?

ozzi

Answer:

- 0.380ºC

Explanation:

The lowering of the freezing point of a solvent is a colligative property ruled by the formula:

$\Delta T_f=K_f\times m\times i$

Where:

ΔTf is the lowering of the freezing point

Kf is the molal freezing constant of the solvent: 1.86 °C/m

m is the molality of the solution

i is the van't Hoff factor: the number of particles (ions) per unit of ionic compound.

a) molality, m

m = number of moles of solute/ kg of solvent

number of moles of CaI₂ = mass in grams/ molar mass

number of moles of CaI₂ = 25.00g / 293.887 g/mol = 0.0850667mol

m = 0.0850667mol/1.25 kg = 0.068053m

b) i

Each unit of CaI₂, ideally, dissociates into 1 Ca⁺ ion and 2 I⁻ ions. Thus, i = 1 + 2 = 3

c) Freezing point lowering

ΔTf = 1.86 °C/m × 0.068053m × 3 = 0.3797ºC ≈ 0.380ºC

<h2>I have problems to upload the full answer in here, so I attach a pdf file with the whole answer.</h2>

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6 0

3 years ago

Suppose a thermometer has marks at every one degree increment and the mercury level on the thermometer is exactly between the 25

alekssr [168]

Answer: 25.5°C

Explanation: take the average of the reading i.e (25 + 26)/2= 25.5

5 0

3 years ago

Two solutions, initially at 24.60 °C, are mixed in a coffee cup calorimeter (Ccal = 15.5 J/°C). When a 100.0 mL volume of 0.100

yulyashka [42]

Answer:

ΔH = -59.6kJ/mol

Explanation:

The reaction that occurs between Ag⁺ and Cl⁻ ions is:

Ag⁺ + Cl⁻ → AgCl(s) + ΔH

To find ΔH we need to obtain moles of reaction and heat released in the reaction because ΔH is defined as heat released per mole of reaction.

Moles of reaction:

Moles of Ag⁺ and Cl⁻ added are:

Ag⁺: 0.100L * (0.100mol / L) = 0.01moles

Cl⁻: 0.100L * (0.200mol / L) 0 0.02 moles

That means limiting reactant is Ag⁺ and moles of reaction are 0.01 moles

Heat released:

To find heat released we must use coffe cup calorimeter equation:

Q = C*m*ΔT

Where C is specific heat of solution (4.18J/g°C), m is the mass of solution (200g because there are 100 + 100mL = 200mL and density of solution is 1g/mL) and ΔT is change in temperature (25.30°C - 24.60°C = 0.70°C).

Replacing:

Q = C*m*ΔT

Q = 4.18J/g°C * 200g * 0.70°C

Q = 585,2J

Is total heat released.

The calorimeter absorbs:

15.5J / °C * 0.7°C = 10.85

Thus, when 0.01 moles reacts, 585.2J + 10.85 = 596.05J are released (Heat released is heat abosrbed by calorimeter + Heat absorbed by water) and ΔH is:

ΔH = 596.05J / 0.01 moles =

ΔH = 59605J / mol =

As heat is released, ΔH < 0.

6 0

3 years ago

The following animals is an endotherm? A. grasshopper B.horse C.lizard D.snake

adoni [48]

Answer:

snake

Explanation:

4 0

3 years ago