Does the addition of a catalyst affect the ΔH of reaction?

1. NaOH mass of a solution of 200g in which its percentage is 25%. What mass of sulfuric acid solution is needed to completely n

Ede4ka [16]

Answer:

$m_{H2SO4$ = 61.25 g

$m_{Na2SO4}$ = 88.75 g

Explanation:

$m_{NaOH}$ = $\frac{200 . 25 }{100}$ = 50 g

⇒ $n_{NaOH}$ = $\frac{50}{40}$ = 1.25 (moles)

2NaOH + H2SO4 ⇒ Na2SO4 + 2H2O

2 : 1 : 1 : 2

1.25 (moles)

⇒ $n_{H2SO4}$ = 1.25 × 1 ÷ 2 = 0.625 (moles) ⇒ $m_{H2SO4}$ = 0.625 × 98 = 61.25 g

$n_{Na2SO4}$ = 1.25 × 1 ÷ 2 = 0.625 (moles) ⇒ $m_{Na2SO4}$ = 0.625 × 142 = 88.75 g

4 0

3 years ago

If 1,079.75 Joules of heat are added to 77.75 grams of water, by how many degrees Celsius would the water increase? Assume water

djyliett [7]

Answer:

If 1,079.75 Joules of heat are added to 77.75 grams of water, by 3.32 degrees Celsius the temperature of water will increase

$\Delta T=3.32 C^{0}$

Explanation:

$q = mC\Delta T$

Here , q = heat added / removed from the substance

m = mass of the substance taken

$\Delta T$ = Change in temperature

C = specific heat capacity of the substance

In liquid state the value of C for water is :

$4.18 J/gC^{0}$

Given values :

q = 1079.75 J

m = 77.75 gram

Insert the value of C, m , q in the given equation

$q = mC\Delta T$

on transposing ,

$\Delta T=\frac{q}{mC}$

$\Delta T=\frac{1079.75}{77.75\times 4.18}$

$\Delta T=3.32 C^{0}$

3 0

3 years ago

Which describes why the magma moves in the direction of

kenny6666 [7]

The magma is heated and becomes less dense by the core moving it toward the crust.

Explanation:

Magma is a molten or partially molten rock form. Magma consists of silicate liquid, although carbonate and sulfide melts occur as well. It moves either to depth or to Earth’s surface and is ejected as lava. Suspended crystals and fragments of un-melted rock get transported in the magma dissolved volatiles may separate as bubbles and some liquid get crystallize during movement.

Several interrelated physical properties determine the characteristics of magma, including chemical composition, viscosity, dissolved gases, and temperature.Magma also form igneous rock.

Therefore the magma is heated and becomes less dense by the core moving it toward the crust.

7 0

3 years ago

Read 2 more answers

A student titrates a 20.00 mL sample of an aqueous borax solution with 1.03 M H2SO4. If 2.07 mL of acid are needed to reach the

RSB [31]

Answer:

The concentration of the borax solution is 0.1066 M

Explanation:

Step 1: Dtaa given

Volume of a sample of aqueous borax solution = 20.00 mL = 0.020 L

Molarity of H2SO4 = 1.03 M

Volume of the H2SO4 = 2.07 mL = 0.00207 L

Step 2: The balanced equation

Na2B4O7*10H2O(borax) + H2SO4 ⇆ Na2SO4 + 4 H3BO3 + 5 H2O

Step 3: Calculate molarity of borax solution

b*Ca*Va = a * Cb*Vb

⇒with B = the coefficient of H2SO4 = 1

⇒with Ca = the concentration of borax = TO BE DETERMINED

⇒with Va = the volume of borax = 0.020 L

⇒with a = the coefficient of borax = 1

⇒with Cb = the concentration of H2SO4 = 1.03 M

⇒with Vb = the volume of H2SO4 = 0.00207 L

Ca*0.020 L = 1.03 M * 0.00207 L

Ca = (1.03 * 0.00207) / 0.020

Ca = 0.1066 M

The concentration of the borax solution is 0.1066 M

6 0

3 years ago

Consider the following unbalanced particulate representation of a chemical equation:

nevsk [136]

Answer:

H2 + I2 --> 2HI

Explanation:

The two reactants are diatomic molecules because they contain two atoms of the same element. Therefore, they would need to have a subscript of "2" next to their symbols.

When balancing an equation, you want the same amount and type of atoms on both sides. By adding a coefficient of "2" in front of the product, two H's and two I's are now on both sides.

3 0

3 years ago