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2 years ago

Which statement best describes the Sun-Earth-Moon system during a spring

2 answers:

4 0

B. The Sun, Earth and the Moon are arranged in a straight line.

Spring (strong) tides occur when the moon is either a full or new moon. During these, the bodies are arranged in a straight line.
Neap (weak) tides occur when the moon is in any quarter phase. During these phases, the earth, moon and sun form a right angle.

iragen [17]2 years ago

3 0

Answer:

The Sun, Earth, and the Moon form a night angle.

Explanation:

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Which body part MOST LIKELY formed this fossil? blood B bones fur D skin

Inessa [10]

Answer:

Bones are the correct answer.

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2 years ago

How many grams of oxygen gas must react to give 2.10g of ZnO?

Advocard [28]

The chemical reaction is written as:

2Zn + O2 = 2ZnO

We are given the amount of the product to be produced from the reaction. We use this value and the relation of the substances in the reaction to calculate what is asked. We do as follows:

2.10 g ZnO ( 1 mol / 81.408 g ) ( 1 mol O2 / 2 mol ZnO ) ( 32 g / 1 mol ) = 0.414 g O2 is needed

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3 years ago

What refers to the attractive forces that exist between molecules?

CaHeK987 [17]

Intermolecular forces are the forces of attraction or repulsion which act between neighboring particles (atoms, molecules, or ions ). These forces are weak compared to the intramolecular forces, such as the covalent or ionic bonds between atoms in a molecule.

8 0

3 years ago

The process in which water changes from a liquid to a vapor is known as __________.

Basile [38]

Hello!
The answer is Evaporation!

When you add enough heat to a liquid, it boils turning into a gas. This is called Evaporation

7 0

3 years ago

Read 2 more answers

For Na2HPO4:(( (Note that for H3PO4, ka1= 6.9x10-3, ka2 = 6.4x10-8, ka3 = 4.8x10-13 ) a) The active anion is H2PO4- b) The activ

Komok [63]

Answer:

Check the explanation

Explanation:

Answer – Given, $H_3PO_4$ acid and there are three Ka values

$K_{a1}=6.9x10^8, K_{a2} = 6.2X10^8, and K_{a3}=4.8X10^{13}$

The transformation of $H_2PO_4- (aq) to HPO_4^2-(aq)$ is the second dissociation, so we need to use the Ka2 = 6.2x10-8 in the Henderson-Hasselbalch equation.

Mass of KH2PO4 = 22.0 g , mass of Na2HPO4 = 32.0 g , volume = 1.00 L

First we need to calculate moles of each

Moles of KH2PO4 = 22.0 g / 136.08 g.mol-1

= 0.162 moles

Moles of Na2HPO4 = 32.0 g /141.96 g.mol-1

= 0.225 moles

[H2PO4-] = 0.162 moles / 1.00 L = 0.162 M

[HPO42-] = 0.225 moles / 1.00 L = 0.225 M

Now we need to calculate the pKa2

pKa2 = -log Ka

= -log 6.2x10-8

= 7.21

We know Henderson-Hasselbalch equation

pH = pKa + log [conjugate base] / [acid]

pH = 7.21 + log 0.225 / 0.162

= 7.35

The pH of a buffer solution obtained by dissolving 22.0 g of KH2PO4 and 32.0 g of Na2HPO4 in water and then diluting to 1.00 L is 7.35

6 0

3 years ago