JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap.min.css">
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.4/css/bootstrap-theme.min.css">
<div class="container">
    <div class="row">
        <div class="col-sm-7"><div class="blue"><img src="https://wiki.creativecommons.org/images/9/97/8256206923_c77e85319e_n.jpg"> Lots of whitespace appears below between 768 to aprx 900 px browser width (tablet dimenions)</div></div>
       <div class="col-sm-5"><div class="black">Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text<br>Line of text</div>
     </div>   
  </div>
 </div>
           
  <div class="container">
    <div class="row">
        <div class="col-sm-7"><div class="red">Red</div>
        <div class="col-sm-5"><div></div>
     </div>   
  </div>

CSS

.black {width:100%; color: #fff;background-color: black ; padding:10px}
.red {width:100%; background-color:red;  color: #fff; padding:10px}
.blue {width:100%; background-color:blue; color: #fff; padding:10px}
img {width:100%}