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2 years ago

Where do the sun rays hit Earth's surface nearly at right angles

Chemistry

1 answer:

hoa [83]2 years ago

8 0

Answer:

The Sun Ray's hit earths surface at Earths Equator

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Phosphorus that is stored in organisms

Mumz [18]

Explanation:

B. Recycles slowly

And it also depends on the organism

3 0

3 years ago

How many moles are in 1.05 g of gold (Au)?

Wittaler [7]

Answer:

0.005 mol

Explanation:

Moles is denoted by given mass divided by the molecular mass ,

Hence ,

n = w / m

n = moles ,

w = given mass ,

m = molecular mass .

From the question ,

w = given mass of Gold = 1.05 g ,

m = molecular mass of Gold = 197 g/mol

Hence , moles can be calculated as -

n = w / m = 1.05 g / 197 g/mol = 0.005 mol

7 0

3 years ago

What is the ratio of [a–]/[ha] at ph 2.75? the pka of formic acid (methanoic acid, h–cooh) is 3.75?

Varvara68 [4.7K]

The dissociation of formic acid is:

$HCOOH \rightleftharpoons HCOO^{-} + H^{+}$

The acid dissociation constant of formic acid, $k_a$ is:

$k_a = \frac{[HCOO^{-}] [H^{+}]}{HCOOH}$

Rearranging the equation:

$\frac{[HCOO^{-}]}{[HCOOH]} = \frac{k_a}{[H_+]}$

pH = 2.75

$pH = -log[H^{+}]$

$[H^{+}]= 10^{-2.75} = 1.78 \times 10^{-3}$

$pk_a = 3.75$

$k_a = 10^{-3.75} = 1.78\times 10^{-4}$

Substituting the values in the equation:

$\frac{[HCOO^{-}]}{[HCOOH]} = \frac{k_a}{[H_+]}$

$\frac{[HCOO^{-}]}{[HCOOH]} = \frac{1.78\times 10^{-4}}{1.78\times 10^{-3}}$

Hence, the ratio is $\frac{1}{10}$ .

4 0

3 years ago

A balloon that had a volume of 3.50 L at 25.0°C is placed in a hot room at 40.0°C. If the pressure remains constant at 1.00 atm,

choli [55]

Answer:

3.676 L.

Explanation:

We can use the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm.

V is the volume of the gas in L.

n is the no. of moles of the gas in mol.

R is the general gas constant,

T is the temperature of the gas in K.

If n and P are constant, and have different values of V and T:

(V₁T₂) = (V₂T₁)

Knowing that:

V₁ = 3.5 L, T₁ = 25°C + 273 = 298 K,

V₂ = ??? L, T₂ = 40°C + 273 = 313 K,

Applying in the above equation

(V₁T₂) = (V₂T₁)

∴ V₂ = (V₁T₂)/(T₁) = (3.5 L)(313 K)/(298 K) = 3.676 L.

7 0

3 years ago

53. A firefighter of mass 80 kg slides down a vertical pole

Zielflug [23.3K]

Answer:

Answer is given below:

Explanation:

Given Data:

mass = 80kg

acceleration = 4 ms

force = 800N

Find out:

friction = ?

Formula:

F-friction = weight - f-net

Solution:

weight = (80)(10)

= 800 N

F-net = ma =(80)(4) = 320N

F-friction = weight - F-net

=800 N - 320N

=480N

Answer :

Friction = 480 N

6 0

3 years ago

Where do the sun rays hit Earth's surface nearly at right angles ​

Where do the sun rays hit Earth's surface nearly at right angles